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| author | Alexei Starovoitov <ast@kernel.org> | 2022-06-29 13:21:53 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-06-29 13:21:53 -0700 |
| commit | d17b557e5eadc9a74bd55191a54841b460c115b7 (patch) | |
| tree | c9d5a8066e9746d08b2dc123694f6c30093363f7 | |
| parent | c5c7358e4c76e2017a6566a29208996fcca75200 (diff) | |
| parent | dca85aac8895708b74c7f2264e3ab5048c02b8b2 (diff) | |
| download | linux-stable-d17b557e5eadc9a74bd55191a54841b460c115b7.tar.gz linux-stable-d17b557e5eadc9a74bd55191a54841b460c115b7.tar.bz2 linux-stable-d17b557e5eadc9a74bd55191a54841b460c115b7.zip | |
Merge branch 'bpf: cgroup_sock lsm flavor'
Stanislav Fomichev says:
====================
This series implements new lsm flavor for attaching per-cgroup programs to
existing lsm hooks. The cgroup is taken out of 'current', unless
the first argument of the hook is 'struct socket'. In this case,
the cgroup association is taken out of socket. The attachment
looks like a regular per-cgroup attachment: we add new BPF_LSM_CGROUP
attach type which, together with attach_btf_id, signals per-cgroup lsm.
Behind the scenes, we allocate trampoline shim program and
attach to lsm. This program looks up cgroup from current/socket
and runs cgroup's effective prog array. The rest of the per-cgroup BPF
stays the same: hierarchy, local storage, retval conventions
(return 1 == success).
Current limitations:
* haven't considered sleepable bpf; can be extended later on
* not sure the verifier does the right thing with null checks;
see latest selftest for details
* total of 10 (global) per-cgroup LSM attach points
v11:
- Martin: address selftest memory & fd leaks
- Martin: address moving into root (instead have another temp leaf cgroup)
- Martin: move tools/include/uapi/linux/bpf.h change from libbpf patch
into 'sync tools' patch
v10:
- Martin: reword commit message, drop outdated items
- Martin: remove rcu_real_lock from __cgroup_bpf_run_lsm_current
- Martin: remove CONFIG_BPF_LSM from cgroup_bpf_release
- Martin: fix leaking shim reference in bpf_cgroup_link_release
- Martin: WARN_ON_ONCE for bpf_trampoline_lookup in bpf_trampoline_unlink_cgroup_shim
- Martin: sync tools/include/linux/btf_ids.h
- Martin: move progs/flags closer to the places where they are used in __cgroup_bpf_query
- Martin: remove sk_clone_security & sctp_bind_connect from bpf_lsm_locked_sockopt_hooks
- Martin: try to determine vmlinux btf_id in bpftool
- Martin: update tools header in a separate commit
- Quentin: do libbpf_find_kernel_btf from the ops that need it
- lkp@intel.com: another build failure
v9:
Major change since last version is the switch to bpf_setsockopt to
change the socket state instead of letting the progs poke socket directly.
This, in turn, highlights the challenge that we need to care about whether
the socket is locked or not when we call bpf_setsockopt. (with my original
example selftest, the hooks are running early in the init phase for this
not to matter).
For now, I've added two btf id lists:
* hooks where we know the socket is locked and it's safe to call bpf_setsockopt
* hooks where we know the socket is _not_ locked, but the hook works on
the socket that's not yet exposed to userspace so it should be safe
(for this mode, special new set of bpf_{s,g}etsockopt helpers
is added; they don't have sock_owned_by_me check)
Going forward, for the rest of the hooks, this might be a good motivation
to expand lsm cgroup to support sleeping bpf and allow the callers to
lock/unlock sockets or have a new bpf_setsockopt variant that does the
locking.
- ifdef around cleanup in cgroup_bpf_release
- Andrii: a few nits in libbpf patches
- Martin: remove unused btf_id_set_index
- Martin: bring back refcnt for cgroup_atype
- Martin: make __cgroup_bpf_query a bit more readable
- Martin: expose dst_prog->aux->attach_btf as attach_btf_obj_id as well
- Martin: reorg check_return_code path for BPF_LSM_CGROUP
- Martin: return directly from check_helper_call (instead of goto err)
- Martin: add note to new warning in check_return_code, print only for void hooks
- Martin: remove confusing shim reuse
- Martin: use bpf_{s,g}etsockopt instead of poking into socket data
- Martin: use CONFIG_CGROUP_BPF in bpf_prog_alloc_no_stats/bpf_prog_free_deferred
v8:
- CI: fix compile issue
- CI: fix broken bpf_cookie
- Yonghong: remove __bpf_trampoline_unlink_prog comment
- Yonghong: move cgroup_atype around to fill the gap
- Yonghong: make bpf_lsm_find_cgroup_shim void
- Yonghong: rename regs to args
- Yonghong: remove if(current) check
- Martin: move refcnt into bpf_link
- Martin: move shim management to bpf_link ops
- Martin: use cgroup_atype for shim only
- Martin: go back to arrays for managing cgroup_atype(s)
- Martin: export bpf_obj_id(aux->attach_btf)
- Andrii: reorder SEC_DEF("lsm_cgroup+")
- Andrii: OPTS_SET instead of OPTS_HAS
- Andrii: rename attach_btf_func_id
- Andrii: move into 1.0 map
v7:
- there were a lot of comments last time, hope I didn't forget anything,
some of the bigger ones:
- Martin: use/extend BTF_SOCK_TYPE_SOCKET
- Martin: expose bpf_set_retval
- Martin: reject 'return 0' at the verifier for 'void' hooks
- Martin: prog_query returns all BPF_LSM_CGROUP, prog_info
returns attach_btf_func_id
- Andrii: split libbpf changes
- Andrii: add field access test to test_progs, not test_verifier (still
using asm though)
- things that I haven't addressed, stating them here explicitly, let
me know if some of these are still problematic:
1. Andrii: exposing only link-based api: seems like the changes
to support non-link-based ones are minimal, couple of lines,
so seems like it worth having it?
2. Alexei: applying cgroup_atype for all cgroup hooks, not only
cgroup lsm: looks a bit harder to apply everywhere that I
originally thought; with lsm cgroup, we have a shim_prog pointer where
we store cgroup_atype; for non-lsm programs, we don't have a
trace program where to store it, so we still need some kind
of global table to map from "static" hook to "dynamic" slot.
So I'm dropping this "can be easily extended" clause from the
description for now. I have converted this whole machinery
to an RCU-managed list to remove synchronize_rcu().
- also note that I had to introduce new bpf_shim_tramp_link and
moved refcnt there; we need something to manage new bpf_tramp_link
v6:
- remove active count & stats for shim program (Martin KaFai Lau)
- remove NULL/error check for btf_vmlinux (Martin)
- don't check cgroup_atype in bpf_cgroup_lsm_shim_release (Martin)
- use old_prog (instead of passed one) in __cgroup_bpf_detach (Martin)
- make sure attach_btf_id is the same in __cgroup_bpf_replace (Martin)
- enable cgroup local storage and test it (Martin)
- properly implement prog query and add bpftool & tests (Martin)
- prohibit non-shared cgroup storage mode for BPF_LSM_CGROUP (Martin)
v5:
- __cgroup_bpf_run_lsm_socket remove NULL sock/sk checks (Martin KaFai Lau)
- __cgroup_bpf_run_lsm_{socket,current} s/prog/shim_prog/ (Martin)
- make sure bpf_lsm_find_cgroup_shim works for hooks without args (Martin)
- __cgroup_bpf_attach make sure attach_btf_id is the same when replacing (Martin)
- call bpf_cgroup_lsm_shim_release only for LSM_CGROUP (Martin)
- drop BPF_LSM_CGROUP from bpf_attach_type_to_tramp (Martin)
- drop jited check from cgroup_shim_find (Martin)
- new patch to convert cgroup_bpf to hlist_node (Jakub Sitnicki)
- new shim flavor for 'struct sock' + list of exceptions (Martin)
v4:
- fix build when jit is on but syscall is off
v3:
- add BPF_LSM_CGROUP to bpftool
- use simple int instead of refcnt_t (to avoid use-after-free
false positive)
v2:
- addressed build bot failures
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
26 files changed, 1432 insertions, 166 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 2c51ca9f7cec..2f460c67f9c7 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1770,6 +1770,10 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, struct bpf_tramp_link *l, int stack_size, int run_ctx_off, bool save_ret) { + void (*exit)(struct bpf_prog *prog, u64 start, + struct bpf_tramp_run_ctx *run_ctx) = __bpf_prog_exit; + u64 (*enter)(struct bpf_prog *prog, + struct bpf_tramp_run_ctx *run_ctx) = __bpf_prog_enter; u8 *prog = *pprog; u8 *jmp_insn; int ctx_cookie_off = offsetof(struct bpf_tramp_run_ctx, bpf_cookie); @@ -1788,15 +1792,21 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, */ emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_1, -run_ctx_off + ctx_cookie_off); + if (p->aux->sleepable) { + enter = __bpf_prog_enter_sleepable; + exit = __bpf_prog_exit_sleepable; + } else if (p->expected_attach_type == BPF_LSM_CGROUP) { + enter = __bpf_prog_enter_lsm_cgroup; + exit = __bpf_prog_exit_lsm_cgroup; + } + /* arg1: mov rdi, progs[i] */ emit_mov_imm64(&prog, BPF_REG_1, (long) p >> 32, (u32) (long) p); /* arg2: lea rsi, [rbp - ctx_cookie_off] */ EMIT4(0x48, 0x8D, 0x75, -run_ctx_off); - if (emit_call(&prog, - p->aux->sleepable ? __bpf_prog_enter_sleepable : - __bpf_prog_enter, prog)) - return -EINVAL; + if (emit_call(&prog, enter, prog)) + return -EINVAL; /* remember prog start time returned by __bpf_prog_enter */ emit_mov_reg(&prog, true, BPF_REG_6, BPF_REG_0); @@ -1840,10 +1850,8 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, emit_mov_reg(&prog, true, BPF_REG_2, BPF_REG_6); /* arg3: lea rdx, [rbp - run_ctx_off] */ EMIT4(0x48, 0x8D, 0x55, -run_ctx_off); - if (emit_call(&prog, - p->aux->sleepable ? __bpf_prog_exit_sleepable : - __bpf_prog_exit, prog)) - return -EINVAL; + if (emit_call(&prog, exit, prog)) + return -EINVAL; *pprog = prog; return 0; diff --git a/include/linux/bpf-cgroup-defs.h b/include/linux/bpf-cgroup-defs.h index 695d1224a71b..7b121bd780eb 100644 --- a/include/linux/bpf-cgroup-defs.h +++ b/include/linux/bpf-cgroup-defs.h @@ -10,6 +10,13 @@ struct bpf_prog_array; +#ifdef CONFIG_BPF_LSM +/* Maximum number of concurrently attachable per-cgroup LSM hooks. */ +#define CGROUP_LSM_NUM 10 +#else +#define CGROUP_LSM_NUM 0 +#endif + enum cgroup_bpf_attach_type { CGROUP_BPF_ATTACH_TYPE_INVALID = -1, CGROUP_INET_INGRESS = 0, @@ -35,6 +42,8 @@ enum cgroup_bpf_attach_type { CGROUP_INET4_GETSOCKNAME, CGROUP_INET6_GETSOCKNAME, CGROUP_INET_SOCK_RELEASE, + CGROUP_LSM_START, + CGROUP_LSM_END = CGROUP_LSM_START + CGROUP_LSM_NUM - 1, MAX_CGROUP_BPF_ATTACH_TYPE }; @@ -47,8 +56,8 @@ struct cgroup_bpf { * have either zero or one element * when BPF_F_ALLOW_MULTI the list can have up to BPF_CGROUP_MAX_PROGS */ - struct list_head progs[MAX_CGROUP_BPF_ATTACH_TYPE]; - u32 flags[MAX_CGROUP_BPF_ATTACH_TYPE]; + struct hlist_head progs[MAX_CGROUP_BPF_ATTACH_TYPE]; + u8 flags[MAX_CGROUP_BPF_ATTACH_TYPE]; /* list of cgroup shared storages */ struct list_head storages; diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index 669d96d074ad..2bd1b5f8de9b 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -23,6 +23,13 @@ struct ctl_table; struct ctl_table_header; struct task_struct; +unsigned int __cgroup_bpf_run_lsm_sock(const void *ctx, + const struct bpf_insn *insn); +unsigned int __cgroup_bpf_run_lsm_socket(const void *ctx, + const struct bpf_insn *insn); +unsigned int __cgroup_bpf_run_lsm_current(const void *ctx, + const struct bpf_insn *insn); + #ifdef CONFIG_CGROUP_BPF #define CGROUP_ATYPE(type) \ @@ -95,7 +102,7 @@ struct bpf_cgroup_link { }; struct bpf_prog_list { - struct list_head node; + struct hlist_node node; struct bpf_prog *prog; struct bpf_cgroup_link *link; struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE]; diff --git a/include/linux/bpf.h b/include/linux/bpf.h index d05e1495a06e..2b21f2a3452f 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -56,6 +56,8 @@ typedef u64 (*bpf_callback_t)(u64, u64, u64, u64, u64); typedef int (*bpf_iter_init_seq_priv_t)(void *private_data, struct bpf_iter_aux_info *aux); typedef void (*bpf_iter_fini_seq_priv_t)(void *private_data); +typedef unsigned int (*bpf_func_t)(const void *, + const struct bpf_insn *); struct bpf_iter_seq_info { const struct seq_operations *seq_ops; bpf_iter_init_seq_priv_t init_seq_private; @@ -792,6 +794,10 @@ void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start, struct bpf_tramp_ u64 notrace __bpf_prog_enter_sleepable(struct bpf_prog *prog, struct bpf_tramp_run_ctx *run_ctx); void notrace __bpf_prog_exit_sleepable(struct bpf_prog *prog, u64 start, struct bpf_tramp_run_ctx *run_ctx); +u64 notrace __bpf_prog_enter_lsm_cgroup(struct bpf_prog *prog, + struct bpf_tramp_run_ctx *run_ctx); +void notrace __bpf_prog_exit_lsm_cgroup(struct bpf_prog *prog, u64 start, + struct bpf_tramp_run_ctx *run_ctx); void notrace __bpf_tramp_enter(struct bpf_tramp_image *tr); void notrace __bpf_tramp_exit(struct bpf_tramp_image *tr); @@ -879,8 +885,7 @@ struct bpf_dispatcher { static __always_inline __nocfi unsigned int bpf_dispatcher_nop_func( const void *ctx, const struct bpf_insn *insnsi, - unsigned int (*bpf_func)(const void *, - const struct bpf_insn *)) + bpf_func_t bpf_func) { return bpf_func(ctx, insnsi); } @@ -909,8 +914,7 @@ int arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs); noinline __nocfi unsigned int bpf_dispatcher_##name##_func( \ const void *ctx, \ const struct bpf_insn *insnsi, \ - unsigned int (*bpf_func)(const void *, \ - const struct bpf_insn *)) \ + bpf_func_t bpf_func) \ { \ return bpf_func(ctx, insnsi); \ } \ @@ -921,8 +925,7 @@ int arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs); unsigned int bpf_dispatcher_##name##_func( \ const void *ctx, \ const struct bpf_insn *insnsi, \ - unsigned int (*bpf_func)(const void *, \ - const struct bpf_insn *)); \ + bpf_func_t bpf_func); \ extern struct bpf_dispatcher bpf_dispatcher_##name; #define BPF_DISPATCHER_FUNC(name) bpf_dispatcher_##name##_func #define BPF_DISPATCHER_PTR(name) (&bpf_dispatcher_##name) @@ -1061,6 +1064,7 @@ struct bpf_prog_aux { struct user_struct *user; u64 load_time; /* ns since boottime */ u32 verified_insns; + int cgroup_atype; /* enum cgroup_bpf_attach_type */ struct bpf_map *cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]; char name[BPF_OBJ_NAME_LEN]; #ifdef CONFIG_SECURITY @@ -1168,6 +1172,11 @@ struct bpf_tramp_link { u64 cookie; }; +struct bpf_shim_tramp_link { + struct bpf_tramp_link link; + struct bpf_trampoline *trampoline; +}; + struct bpf_tracing_link { struct bpf_tramp_link link; enum bpf_attach_type attach_type; @@ -1246,6 +1255,9 @@ struct bpf_dummy_ops { int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr, union bpf_attr __user *uattr); #endif +int bpf_trampoline_link_cgroup_shim(struct bpf_prog *prog, + int cgroup_atype); +void bpf_trampoline_unlink_cgroup_shim(struct bpf_prog *prog); #else static inline const struct bpf_struct_ops *bpf_struct_ops_find(u32 type_id) { @@ -1269,6 +1281,14 @@ static inline int bpf_struct_ops_map_sys_lookup_elem(struct bpf_map *map, { return -EINVAL; } +static inline int bpf_trampoline_link_cgroup_shim(struct bpf_prog *prog, + int cgroup_atype) +{ + return -EOPNOTSUPP; +} +static inline void bpf_trampoline_unlink_cgroup_shim(struct bpf_prog *prog) +{ +} #endif struct bpf_array { @@ -2366,9 +2386,13 @@ extern const struct bpf_func_proto bpf_for_each_map_elem_proto; extern const struct bpf_func_proto bpf_btf_find_by_name_kind_proto; extern const struct bpf_func_proto bpf_sk_setsockopt_proto; extern const struct bpf_func_proto bpf_sk_getsockopt_proto; +extern const struct bpf_func_proto bpf_unlocked_sk_setsockopt_proto; +extern const struct bpf_func_proto bpf_unlocked_sk_getsockopt_proto; extern const struct bpf_func_proto bpf_find_vma_proto; extern const struct bpf_func_proto bpf_loop_proto; extern const struct bpf_func_proto bpf_copy_from_user_task_proto; +extern const struct bpf_func_proto bpf_set_retval_proto; +extern const struct bpf_func_proto bpf_get_retval_proto; const struct bpf_func_proto *tracing_prog_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); @@ -2522,4 +2546,12 @@ void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, void *data, void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr); int bpf_dynptr_check_size(u32 size); +#ifdef CONFIG_BPF_LSM +void bpf_cgroup_atype_get(u32 attach_btf_id, int cgroup_atype); +void bpf_cgroup_atype_put(int cgroup_atype); +#else +static inline void bpf_cgroup_atype_get(u32 attach_btf_id, int cgroup_atype) {} +static inline void bpf_cgroup_atype_put(int cgroup_atype) {} +#endif /* CONFIG_BPF_LSM */ + #endif /* _LINUX_BPF_H */ diff --git a/include/linux/bpf_lsm.h b/include/linux/bpf_lsm.h index 479c101546ad..4bcf76a9bb06 100644 --- a/include/linux/bpf_lsm.h +++ b/include/linux/bpf_lsm.h @@ -42,6 +42,8 @@ extern const struct bpf_func_proto bpf_inode_storage_get_proto; extern const struct bpf_func_proto bpf_inode_storage_delete_proto; void bpf_inode_storage_free(struct inode *inode); +void bpf_lsm_find_cgroup_shim(const struct bpf_prog *prog, bpf_func_t *bpf_func); + #else /* !CONFIG_BPF_LSM */ static inline bool bpf_lsm_is_sleepable_hook(u32 btf_id) @@ -65,6 +67,11 @@ static inline void bpf_inode_storage_free(struct inode *inode) { } +static inline void bpf_lsm_find_cgroup_shim(const struct bpf_prog *prog, + bpf_func_t *bpf_func) +{ +} + #endif /* CONFIG_BPF_LSM */ #endif /* _LINUX_BPF_LSM_H */ diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h index 335a19092368..252a4befeab1 100644 --- a/include/linux/btf_ids.h +++ b/include/linux/btf_ids.h @@ -179,7 +179,8 @@ extern struct btf_id_set name; BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, udp_sock) \ BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock) \ BTF_SOCK_TYPE(BTF_SOCK_TYPE_UNIX, unix_sock) \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_MPTCP, mptcp_sock) + BTF_SOCK_TYPE(BTF_SOCK_TYPE_MPTCP, mptcp_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCKET, socket) enum { #define BTF_SOCK_TYPE(name, str) name, diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index e81362891596..ad9e7311c4cf 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -998,6 +998,7 @@ enum bpf_attach_type { BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, BPF_PERF_EVENT, BPF_TRACE_KPROBE_MULTI, + BPF_LSM_CGROUP, __MAX_BPF_ATTACH_TYPE }; @@ -1431,6 +1432,7 @@ union bpf_attr { __u32 attach_flags; __aligned_u64 prog_ids; __u32 prog_cnt; + __aligned_u64 prog_attach_flags; /* output: per-program attach_flags */ } query; struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */ @@ -6075,6 +6077,8 @@ struct bpf_prog_info { __u64 run_cnt; __u64 recursion_misses; __u32 verified_insns; + __u32 attach_btf_obj_id; + __u32 attach_btf_id; } __attribute__((aligned(8))); struct bpf_map_info { diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c index c1351df9f7ee..d469b7f3deef 100644 --- a/kernel/bpf/bpf_lsm.c +++ b/kernel/bpf/bpf_lsm.c @@ -16,6 +16,7 @@ #include <linux/bpf_local_storage.h> #include <linux/btf_ids.h> #include <linux/ima.h> +#include <linux/bpf-cgroup.h> /* For every LSM hook that allows attachment of BPF programs, declare a nop * function where a BPF program can be attached. @@ -35,6 +36,57 @@ BTF_SET_START(bpf_lsm_hooks) #undef LSM_HOOK BTF_SET_END(bpf_lsm_hooks) +/* List of LSM hooks that should operate on 'current' cgroup regardless + * of function signature. + */ +BTF_SET_START(bpf_lsm_current_hooks) +/* operate on freshly allocated sk without any cgroup association */ +BTF_ID(func, bpf_lsm_sk_alloc_security) +BTF_ID(func, bpf_lsm_sk_free_security) +BTF_SET_END(bpf_lsm_current_hooks) + +/* List of LSM hooks that trigger while the socket is properly locked. + */ +BTF_SET_START(bpf_lsm_locked_sockopt_hooks) +BTF_ID(func, bpf_lsm_socket_sock_rcv_skb) +BTF_ID(func, bpf_lsm_sock_graft) +BTF_ID(func, bpf_lsm_inet_csk_clone) +BTF_ID(func, bpf_lsm_inet_conn_established) +BTF_SET_END(bpf_lsm_locked_sockopt_hooks) + +/* List of LSM hooks that trigger while the socket is _not_ locked, + * but it's ok to call bpf_{g,s}etsockopt because the socket is still + * in the early init phase. + */ +BTF_SET_START(bpf_lsm_unlocked_sockopt_hooks) +BTF_ID(func, bpf_lsm_socket_post_create) +BTF_ID(func, bpf_lsm_socket_socketpair) +BTF_SET_END(bpf_lsm_unlocked_sockopt_hooks) + +void bpf_lsm_find_cgroup_shim(const struct bpf_prog *prog, + bpf_func_t *bpf_func) +{ + const struct btf_param *args; + + if (btf_type_vlen(prog->aux->attach_func_proto) < 1 || + btf_id_set_contains(&bpf_lsm_current_hooks, + prog->aux->attach_btf_id)) { + *bpf_func = __cgroup_bpf_run_lsm_current; + return; + } + + args = btf_params(prog->aux->attach_func_proto); + +#ifdef CONFIG_NET + if (args[0].type == btf_sock_ids[BTF_SOCK_TYPE_SOCKET]) + *bpf_func = __cgroup_bpf_run_lsm_socket; + else if (args[0].type == btf_sock_ids[BTF_SOCK_TYPE_SOCK]) + *bpf_func = __cgroup_bpf_run_lsm_sock; + else +#endif + *bpf_func = __cgroup_bpf_run_lsm_current; +} + int bpf_lsm_verify_prog(struct bpf_verifier_log *vlog, const struct bpf_prog *prog) { @@ -158,6 +210,35 @@ bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return prog->aux->sleepable ? &bpf_ima_file_hash_proto : NULL; case BPF_FUNC_get_attach_cookie: return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto : NULL; + case BPF_FUNC_get_local_storage: + return prog->expected_attach_type == BPF_LSM_CGROUP ? + &bpf_get_local_storage_proto : NULL; + case BPF_FUNC_set_retval: + return prog->expected_attach_type == BPF_LSM_CGROUP ? + &bpf_set_retval_proto : NULL; + case BPF_FUNC_get_retval: + return prog->expected_attach_type == BPF_LSM_CGROUP ? + &bpf_get_retval_proto : NULL; + case BPF_FUNC_setsockopt: + if (prog->expected_attach_type != BPF_LSM_CGROUP) + return NULL; + if (btf_id_set_contains(&bpf_lsm_locked_sockopt_hooks, + prog->aux->attach_btf_id)) + return &bpf_sk_setsockopt_proto; + if (btf_id_set_contains(&bpf_lsm_unlocked_sockopt_hooks, + prog->aux->attach_btf_id)) + return &bpf_unlocked_sk_setsockopt_proto; + return NULL; + case BPF_FUNC_getsockopt: + if (prog->expected_attach_type != BPF_LSM_CGROUP) + return NULL; + if (btf_id_set_contains(&bpf_lsm_locked_sockopt_hooks, + prog->aux->attach_btf_id)) + return &bpf_sk_getsockopt_proto; + if (btf_id_set_contains(&bpf_lsm_unlocked_sockopt_hooks, + prog->aux->attach_btf_id)) + return &bpf_unlocked_sk_getsockopt_proto; + return NULL; default: return tracing_prog_func_proto(func_id, prog); } diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 2e2066d6af94..8d3c7ab8af46 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -5363,6 +5363,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type, if (arg == nr_args) { switch (prog->expected_attach_type) { + case BPF_LSM_CGROUP: case BPF_LSM_MAC: case BPF_TRACE_FEXIT: /* When LSM programs are attached to void LSM hooks diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 7a394f7c205c..59b7eb60d5b4 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -14,6 +14,8 @@ #include <linux/string.h> #include <linux/bpf.h> #include <linux/bpf-cgroup.h> +#include <linux/bpf_lsm.h> +#include <linux/bpf_verifier.h> #include <net/sock.h> #include <net/bpf_sk_storage.h> @@ -61,6 +63,132 @@ bpf_prog_run_array_cg(const struct cgroup_bpf *cgrp, return run_ctx.retval; } +unsigned int __cgroup_bpf_run_lsm_sock(const void *ctx, + const struct bpf_insn *insn) +{ + const struct bpf_prog *shim_prog; + struct sock *sk; + struct cgroup *cgrp; + int ret = 0; + u64 *args; + + args = (u64 *)ctx; + sk = (void *)(unsigned long)args[0]; + /*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/ + shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi)); + + cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); + if (likely(cgrp)) + ret = bpf_prog_run_array_cg(&cgrp->bpf, + shim_prog->aux->cgroup_atype, + ctx, bpf_prog_run, 0, NULL); + return ret; +} + +unsigned int __cgroup_bpf_run_lsm_socket(const void *ctx, + const struct bpf_insn *insn) +{ + const struct bpf_prog *shim_prog; + struct socket *sock; + struct cgroup *cgrp; + int ret = 0; + u64 *args; + + args = (u64 *)ctx; + sock = (void *)(unsigned long)args[0]; + /*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/ + shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi)); + + cgrp = sock_cgroup_ptr(&sock->sk->sk_cgrp_data); + if (likely(cgrp)) + ret = bpf_prog_run_array_cg(&cgrp->bpf, + shim_prog->aux->cgroup_atype, + ctx, bpf_prog_run, 0, NULL); + return ret; +} + +unsigned int __cgroup_bpf_run_lsm_current(const void *ctx, + const struct bpf_insn *insn) +{ + const struct bpf_prog *shim_prog; + struct cgroup *cgrp; + int ret = 0; + + /*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/ + shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi)); + + /* We rely on trampoline's __bpf_prog_enter_lsm_cgroup to grab RCU read lock. */ + cgrp = task_dfl_cgroup(current); + if (likely(cgrp)) + ret = bpf_prog_run_array_cg(&cgrp->bpf, + shim_prog->aux->cgroup_atype, + ctx, bpf_prog_run, 0, NULL); + return ret; +} + +#ifdef CONFIG_BPF_LSM +struct cgroup_lsm_atype { + u32 attach_btf_id; + int refcnt; +}; + +static struct cgroup_lsm_atype cgroup_lsm_atype[CGROUP_LSM_NUM]; + +static enum cgroup_bpf_attach_type +bpf_cgroup_atype_find(enum bpf_attach_type attach_type, u32 attach_btf_id) +{ + int i; + + lockdep_assert_held(&cgroup_mutex); + + if (attach_type != BPF_LSM_CGROUP) + return to_cgroup_bpf_attach_type(attach_type); + + for (i = 0; i < ARRAY_SIZE(cgroup_lsm_atype); i++) + if (cgroup_lsm_atype[i].attach_btf_id == attach_btf_id) + return CGROUP_LSM_START + i; + + for (i = 0; i < ARRAY_SIZE(cgroup_lsm_atype); i++) + if (cgroup_lsm_atype[i].attach_btf_id == 0) + return CGROUP_LSM_START + i; + + return -E2BIG; + +} + +void bpf_cgroup_atype_get(u32 attach_btf_id, int cgroup_atype) +{ + int i = cgroup_atype - CGROUP_LSM_START; + + lockdep_assert_held(&cgroup_mutex); + + WARN_ON_ONCE(cgroup_lsm_atype[i].attach_btf_id && + cgroup_lsm_atype[i].attach_btf_id != attach_btf_id); + + cgroup_lsm_atype[i].attach_btf_id = attach_btf_id; + cgroup_lsm_atype[i].refcnt++; +} + +void bpf_cgroup_atype_put(int cgroup_atype) +{ + int i = cgroup_atype - CGROUP_LSM_START; + + mutex_lock(&cgroup_mutex); + if (--cgroup_lsm_atype[i].refcnt <= 0) + cgroup_lsm_atype[i].attach_btf_id = 0; + WARN_ON_ONCE(cgroup_lsm_atype[i].refcnt < 0); + mutex_unlock(&cgroup_mutex); +} +#else +static enum cgroup_bpf_attach_type +bpf_cgroup_atype_find(enum bpf_attach_type attach_type, u32 attach_btf_id) +{ + if (attach_type != BPF_LSM_CGROUP) + return to_cgroup_bpf_attach_type(attach_type); + return -EOPNOTSUPP; +} +#endif /* CONFIG_BPF_LSM */ + void cgroup_bpf_offline(struct cgroup *cgrp) { cgroup_get(cgrp); @@ -157,15 +285,22 @@ static void cgroup_bpf_release(struct work_struct *work) mutex_lock(&cgroup_mutex); for (atype = 0; atype < ARRAY_SIZE(cgrp->bpf.progs); atype++) { - struct list_head *progs = &cgrp->bpf.progs[atype]; - struct bpf_prog_list *pl, *pltmp; + struct hlist_head *progs = &cgrp->bpf.progs[atype]; + struct bpf_prog_list *pl; + struct hlist_node *pltmp; - list_for_each_entry_safe(pl, pltmp, progs, node) { - list_del(&pl->node); - if (pl->prog) + hlist_for_each_entry_safe(pl, pltmp, progs, node) { + hlist_del(&pl->node); + if (pl->prog) { + if (pl->prog->expected_attach_type == BPF_LSM_CGROUP) + bpf_trampoline_unlink_cgroup_shim(pl->prog); bpf_prog_put(pl->prog); - if (pl->link) + } + if (pl->link) { + if (pl->link->link.prog->expected_attach_type == BPF_LSM_CGROUP) + bpf_trampoline_unlink_cgroup_shim(pl->link->link.prog); bpf_cgroup_link_auto_detach(pl->link); + } kfree(pl); static_branch_dec(&cgroup_bpf_enabled_key[atype]); } @@ -217,12 +352,12 @@ static struct bpf_prog *prog_list_prog(struct bpf_prog_list *pl) /* count number of elements in the list. * it's slow but the list cannot be long */ -static u32 prog_list_length(struct list_head *head) +static u32 prog_list_length(struct hlist_head *head) { struct bpf_prog_list *pl; u32 cnt = 0; - list_for_each_entry(pl, head, node) { + hlist_for_each_entry(pl, head, node) { if (!prog_list_prog(pl)) continue; cnt++; @@ -291,7 +426,7 @@ static int compute_effective_progs(struct cgroup *cgrp, if (cnt > 0 && !(p->bpf.flags[atype] & BPF_F_ALLOW_MULTI)) continue; - list_for_each_entry(pl, &p->bpf.progs[atype], node) { + hlist_for_each_entry(pl, &p->bpf.progs[atype], node) { if (!prog_list_prog(pl)) continue; @@ -342,7 +477,7 @@ int cgroup_bpf_inherit(struct cgroup *cgrp) cgroup_bpf_get(p); for (i = 0; i < NR; i++) - INIT_LIST_HEAD(&cgrp->bpf.progs[i]); + INIT_HLIST_HEAD(&cgrp->bpf.progs[i]); INIT_LIST_HEAD(&cgrp->bpf.storages); @@ -418,7 +553,7 @@ cleanup: #define BPF_CGROUP_MAX_PROGS 64 -static struct bpf_prog_list *find_attach_entry(struct list_head *progs, +static struct bpf_prog_list *find_attach_entry(struct hlist_head *progs, struct bpf_prog *prog, struct bpf_cgroup_link *link, struct bpf_prog *replace_prog, @@ -428,12 +563,12 @@ static struct bpf_prog_list *find_attach_entry(struct list_head *progs, /* single-attach case */ if (!allow_multi) { - if (list_empty(progs)) + if (hlist_empty(progs)) return NULL; - return list_first_entry(progs, typeof(*pl), node); + return hlist_entry(progs->first, typeof(*pl), node); } - list_for_each_entry(pl, progs, node) { + hlist_for_each_entry(pl, progs, node) { if (prog && pl->prog == prog && prog != replace_prog) /* disallow attaching the same prog twice */ return ERR_PTR(-EINVAL); @@ -444,7 +579,7 @@ static struct bpf_prog_list *find_attach_entry(struct list_head *progs, /* direct prog multi-attach w/ replacement case */ if (replace_prog) { - list_for_each_entry(pl, progs, node) { + hlist_for_each_entry(pl, progs, node) { if (pl->prog == replace_prog) /* a match found */ return pl; @@ -478,9 +613,10 @@ static int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *old_prog = NULL; struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {}; struct bpf_cgroup_storage *new_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {}; + struct bpf_prog *new_prog = prog ? : link->link.prog; enum cgroup_bpf_attach_type atype; struct bpf_prog_list *pl; - struct list_head *progs; + struct hlist_head *progs; int err; if (((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI)) || @@ -494,7 +630,7 @@ static int __cgroup_bpf_attach(struct cgroup *cgrp, /* replace_prog implies BPF_F_REPLACE, and vice versa */ return -EINVAL; - atype = to_cgroup_bpf_attach_type(type); + atype = bpf_cgroup_atype_find(type, new_prog->aux->attach_btf_id); if (atype < 0) return -EINVAL; @@ -503,7 +639,7 @@ static int __cgroup_bpf_attach(struct cgroup *cgrp, if (!hierarchy_allows_attach(cgrp, atype)) return -EPERM; - if (!list_empty(progs) && cgrp->bpf.flags[atype] != saved_flags) + if (!hlist_empty(progs) && cgrp->bpf.flags[atype] != saved_flags) /* Disallow attaching non-overridable on top * of existing overridable in this cgroup. * Disallow attaching multi-prog if overridable or none @@ -525,12 +661,22 @@ static int __cgroup_bpf_attach(struct cgroup *cgrp, if (pl) { old_prog = pl->prog; } else { + struct hlist_node *last = NULL; + pl = kmalloc(sizeof(*pl), GFP_KERNEL); if (!pl) { bpf_cgroup_storages_free(new_storage); return -ENOMEM; } - list_add_tail(&pl->node, progs); + if (hlist_empty(progs)) + hlist_add_head(&pl->node, progs); + else + hlist_for_each(last, progs) { + if (last->next) + continue; + hlist_add_behind(&pl->node, last); + break; + } } pl->prog = prog; @@ -538,17 +684,30 @@ static int __cgroup_bpf_attach(struct cgroup *cgrp, bpf_cgroup_storages_assign(pl->storage, storage); cgrp->bpf.flags[atype] = saved_flags; + if (type == BPF_LSM_CGROUP) { + err = bpf_trampoline_link_cgroup_shim(new_prog, atype); + if (err) + goto cleanup; + } + err = update_effective_progs(cgrp, atype); if (err) - goto cleanup; + goto cleanup_trampoline; - if (old_prog) + if (old_prog) { + if (type == BPF_LSM_CGROUP) + bpf_trampoline_unlink_cgroup_shim(old_prog); bpf_prog_put(old_prog); - else + } else { static_branch_inc(&cgroup_bpf_enabled_key[atype]); + } bpf_cgroup_storages_link(new_storage, cgrp, type); return 0; +cleanup_trampoline: + if (type == BPF_LSM_CGROUP) + bpf_trampoline_unlink_cgroup_shim(new_prog); + cleanup: if (old_prog) { pl->prog = old_prog; @@ -556,7 +715,7 @@ cleanup: } bpf_cgroup_storages_free(new_storage); if (!old_prog) { - list_del(&pl->node); + hlist_del(&pl->node); kfree(pl); } return err; @@ -587,7 +746,7 @@ static void replace_effective_prog(struct cgroup *cgrp, struct cgroup_subsys_state *css; struct bpf_prog_array *progs; struct bpf_prog_list *pl; - struct list_head *head; + struct hlist_head *head; struct cgroup *cg; int pos; @@ -603,7 +762,7 @@ static void replace_effective_prog(struct cgroup *cgrp, continue; head = &cg->bpf.progs[atype]; - list_for_each_entry(pl, head, node) { + hlist_for_each_entry(pl, head, node) { if (!prog_list_prog(pl)) continue; if (pl->link == link) @@ -637,10 +796,10 @@ static int __cgroup_bpf_replace(struct cgroup *cgrp, enum cgroup_bpf_attach_type atype; struct bpf_prog *old_prog; struct bpf_prog_list *pl; - struct list_head *progs; + struct hlist_head *progs; bool found = false; - atype = to_cgroup_bpf_attach_type(link->type); + atype = bpf_cgroup_atype_find(link->type, new_prog->aux->attach_btf_id); if (atype < 0) return -EINVAL; @@ -649,7 +808,7 @@ static int __cgroup_bpf_replace(struct cgroup *cgrp, if (link->link.prog->type != new_prog->type) return -EINVAL; - list_for_each_entry(pl, progs, node) { + hlist_for_each_entry(pl, progs, node) { if (pl->link == link) { found = true; break; @@ -688,7 +847,7 @@ out_unlock: return ret; } -static struct bpf_prog_list *find_detach_entry(struct list_head *progs, +static struct bpf_prog_list *find_detach_entry(struct hlist_head *progs, struct bpf_prog *prog, struct bpf_cgroup_link *link, bool allow_multi) @@ -696,14 +855,14 @@ static struct bpf_prog_list *find_detach_entry(struct list_head *progs, struct bpf_prog_list *pl; if (!allow_multi) { - if (list_empty(progs)) + if (hlist_empty(progs)) /* report error when trying to detach and nothing is attached */ return ERR_PTR(-ENOENT); /* to maintain backward compatibility NONE and OVERRIDE cgroups * allow detaching with invalid FD (prog==NULL) in legacy mode */ - return list_first_entry(progs, typeof(*pl), node); + return hlist_entry(progs->first, typeof(*pl), node); } if (!prog && !link) @@ -713,7 +872,7 @@ static struct bpf_prog_list *find_detach_entry(struct list_head *progs, return ERR_PTR(-EINVAL); /* find the prog or link and detach it */ - list_for_each_entry(pl, progs, node) { + hlist_for_each_entry(pl, progs, node) { if (pl->prog == prog && pl->link == link) return pl; } @@ -737,7 +896,7 @@ static void purge_effective_progs(struct cgroup *cgrp, struct bpf_prog *prog, struct cgroup_subsys_state *css; struct bpf_prog_array *progs; struct bpf_prog_list *pl; - struct list_head *head; + struct hlist_head *head; struct cgroup *cg; int pos; @@ -754,7 +913,7 @@ static void purge_effective_progs(struct cgroup *cgrp, struct bpf_prog *prog, continue; head = &cg->bpf.progs[atype]; - list_for_each_entry(pl, head, node) { + hlist_for_each_entry(pl, head, node) { if (!prog_list_prog(pl)) continue; if (pl->prog == prog && pl->link == link) @@ -791,10 +950,16 @@ static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, enum cgroup_bpf_attach_type atype; struct bpf_prog *old_prog; struct bpf_prog_list *pl; - struct list_head *progs; + struct hlist_head *progs; + u32 attach_btf_id = 0; u32 flags; - atype = to_cgroup_bpf_attach_type(type); + if (prog) + attach_btf_id = prog->aux->attach_btf_id; + if (link) + attach_btf_id = link->link.prog->aux->attach_btf_id; + + atype = bpf_cgroup_atype_find(type, attach_btf_id); if (atype < 0) return -EINVAL; @@ -822,13 +987,17 @@ static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, } /* now can actually delete it from this cgroup list */ - list_del(&pl->node); + hlist_del(&pl->node); + kfree(pl); - if (list_empty(progs)) + if (hlist_empty(progs)) /* last program was detached, reset flags to zero */ cgrp->bpf.flags[atype] = 0; - if (old_prog) + if (old_prog) { + if (type == BPF_LSM_CGROUP) + bpf_trampoline_unlink_cgroup_shim(old_prog); bpf_prog_put(old_prog); + } static_branch_dec(&cgroup_bpf_enabled_key[atype]); return 0; } @@ -848,57 +1017,90 @@ static int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, union bpf_attr __user *uattr) { + __u32 __user *prog_attach_flags = u64_to_user_ptr(attr->query.prog_attach_flags); __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); enum bpf_attach_type type = attr->query.attach_type; + enum cgroup_bpf_attach_type from_atype, to_atype; enum cgroup_bpf_attach_type atype; struct bpf_prog_array *effective; - struct list_head *progs; - struct bpf_prog *prog; int cnt, ret = 0, i; + int total_cnt = 0; u32 flags; - atype = to_cgroup_bpf_attach_type(type); - if (atype < 0) - return -EINVAL; - - progs = &cgrp->bpf.progs[atype]; - flags = cgrp->bpf.flags[atype]; + if (type == BPF_LSM_CGROUP) { + if (attr->query.prog_cnt && prog_ids && !prog_attach_flags) + return -EINVAL; - effective = rcu_dereference_protected(cgrp->bpf.effective[atype], - lockdep_is_held(&cgroup_mutex)); + from_atype = CGROUP_LSM_START; + to_atype = CGROUP_LSM_END; + flags = 0; + } else { + from_atype = to_cgroup_bpf_attach_type(type); + if (from_atype < 0) + return -EINVAL; + to_atype = from_atype; + flags = cgrp->bpf.flags[from_atype]; + } - if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) - cnt = bpf_prog_array_length(effective); - else - cnt = prog_list_length(progs); + for (atype = from_atype; atype <= to_atype; atype++) { + if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) { + effective = rcu_dereference_protected(cgrp->bpf.effective[atype], + lockdep_is_held(&cgroup_mutex)); + total_cnt += bpf_prog_array_length(effective); + } else { + total_cnt += prog_list_length(&cgrp->bpf.progs[atype]); + } + } if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags))) return -EFAULT; - if (copy_to_user(&uattr->query.prog_cnt, &cnt, sizeof(cnt))) + if (copy_to_user(&uattr->query.prog_cnt, &total_cnt, sizeof(total_cnt))) return -EFAULT; - if (attr->query.prog_cnt == 0 || !prog_ids || !cnt) + if (attr->query.prog_cnt == 0 || !prog_ids || !total_cnt) /* return early if user requested only program count + flags */ return 0; - if (attr->query.prog_cnt < cnt) { - cnt = attr->query.prog_cnt; + + if (attr->query.prog_cnt < total_cnt) { + total_cnt = attr->query.prog_cnt; ret = -ENOSPC; } - if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) { - return bpf_prog_array_copy_to_user(effective, prog_ids, cnt); - } else { - struct bpf_prog_list *pl; - u32 id; - - i = 0; - list_for_each_entry(pl, progs, node) { - prog = prog_list_prog(pl); - id = prog->aux->id; - if (copy_to_user(prog_ids + i, &id, sizeof(id))) - return -EFAULT; - if (++i == cnt) - break; + for (atype = from_atype; atype <= to_atype && total_cnt; atype++) { + if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) { + effective = rcu_dereference_protected(cgrp->bpf.effective[atype], + lockdep_is_held(&cgroup_mutex)); + cnt = min_t(int, bpf_prog_array_length(effective), total_cnt); + ret = bpf_prog_array_copy_to_user(effective, prog_ids, cnt); + } else { + struct hlist_head *progs; + struct bpf_prog_list *pl; + struct bpf_prog *prog; + u32 id; + + progs = &cgrp->bpf.progs[atype]; + cnt = min_t(int, prog_list_length(progs), total_cnt); + i = 0; + hlist_for_each_entry(pl, progs, node) { + prog = prog_list_prog(pl); + id = prog->aux->id; + if (copy_to_user(prog_ids + i, &id, sizeof(id))) + return -EFAULT; + if (++i == cnt) + break; + } } + + if (prog_attach_flags) { + flags = cgrp->bpf.flags[atype]; + + for (i = 0; i < cnt; i++) + if (copy_to_user(prog_attach_flags + i, &flags, sizeof(flags))) + return -EFAULT; + prog_attach_flags += cnt; + } + + prog_ids += cnt; + total_cnt -= cnt; } return ret; } @@ -987,6 +1189,8 @@ static void bpf_cgroup_link_release(struct bpf_link *link) WARN_ON(__cgroup_bpf_detach(cg_link->cgroup, NULL, cg_link, cg_link->type)); + if (cg_link->type == BPF_LSM_CGROUP) + bpf_trampoline_unlink_cgroup_shim(cg_link->link.prog); cg = cg_link->cgroup; cg_link->cgroup = NULL; @@ -1331,7 +1535,7 @@ BPF_CALL_0(bpf_get_retval) return ctx->retval; } -static const struct bpf_func_proto bpf_get_retval_proto = { +const struct bpf_func_proto bpf_get_retval_proto = { .func = bpf_get_retval, .gpl_only = false, .ret_type = RET_INTEGER, @@ -1346,7 +1550,7 @@ BPF_CALL_1(bpf_set_retval, int, retval) return 0; } -static const struct bpf_func_proto bpf_set_retval_proto = { +const struct bpf_func_proto bpf_set_retval_proto = { .func = bpf_set_retval, .gpl_only = false, .ret_type = RET_INTEGER, diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index f023cb399e3f..805c2ad5c793 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -107,6 +107,9 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag fp->aux->prog = fp; fp->jit_requested = ebpf_jit_enabled(); fp->blinding_requested = bpf_jit_blinding_enabled(fp); +#ifdef CONFIG_CGROUP_BPF + aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID; +#endif INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode); mutex_init(&fp->aux->used_maps_mutex); @@ -2570,6 +2573,10 @@ static void bpf_prog_free_deferred(struct work_struct *work) #ifdef CONFIG_BPF_SYSCALL bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab); #endif +#ifdef CONFIG_CGROUP_BPF + if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID) + bpf_cgroup_atype_put(aux->cgroup_atype); +#endif bpf_free_used_maps(aux); bpf_free_used_btfs(aux); if (bpf_prog_is_dev_bound(aux)) @@ -2666,6 +2673,8 @@ const struct bpf_func_proto bpf_get_local_storage_proto __weak; const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak; const struct bpf_func_proto bpf_snprintf_btf_proto __weak; const struct bpf_func_proto bpf_seq_printf_btf_proto __weak; +const struct bpf_func_proto bpf_set_retval_proto __weak; +const struct bpf_func_proto bpf_get_retval_proto __weak; const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void) { diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 7d5af5b99f0d..ab688d85b2c6 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3416,6 +3416,8 @@ attach_type_to_prog_type(enum bpf_attach_type attach_type) return BPF_PROG_TYPE_SK_LOOKUP; case BPF_XDP: return BPF_PROG_TYPE_XDP; + case BPF_LSM_CGROUP: + return BPF_PROG_TYPE_LSM; default: return BPF_PROG_TYPE_UNSPEC; } @@ -3469,6 +3471,11 @@ static int bpf_prog_attach(const union bpf_attr *attr) case BPF_PROG_TYPE_CGROUP_SOCKOPT: case BPF_PROG_TYPE_CGROUP_SYSCTL: case BPF_PROG_TYPE_SOCK_OPS: + case BPF_PROG_TYPE_LSM: + if (ptype == BPF_PROG_TYPE_LSM && + prog->expected_attach_type != BPF_LSM_CGROUP) + return -EINVAL; + ret = cgroup_bpf_prog_attach(attr, ptype, prog); break; default: @@ -3506,13 +3513,14 @@ static int bpf_prog_detach(const union bpf_attr *attr) case BPF_PROG_TYPE_CGROUP_SOCKOPT: case BPF_PROG_TYPE_CGROUP_SYSCTL: case BPF_PROG_TYPE_SOCK_OPS: + case BPF_PROG_TYPE_LSM: return cgroup_bpf_prog_detach(attr, ptype); default: return -EINVAL; } } -#define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt +#define BPF_PROG_QUERY_LAST_FIELD query.prog_attach_flags static int bpf_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr) @@ -3548,6 +3556,7 @@ static int bpf_prog_query(const union bpf_attr *attr, case BPF_CGROUP_SYSCTL: case BPF_CGROUP_GETSOCKOPT: case BPF_CGROUP_SETSOCKOPT: + case BPF_LSM_CGROUP: return cgroup_bpf_prog_query(attr, uattr); case BPF_LIRC_MODE2: return lirc_prog_query(attr, uattr); @@ -4058,6 +4067,11 @@ static int bpf_prog_get_info_by_fd(struct file *file, if (prog->aux->btf) info.btf_id = btf_obj_id(prog->aux->btf); + info.attach_btf_id = prog->aux->attach_btf_id; + if (prog->aux->attach_btf) + info.attach_btf_obj_id = btf_obj_id(prog->aux->attach_btf); + else if (prog->aux->dst_prog) + info.attach_btf_obj_id = btf_obj_id(prog->aux->dst_prog->aux->attach_btf); ulen = info.nr_func_info; info.nr_func_info = prog->aux->func_info_cnt; @@ -4540,6 +4554,8 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr) ret = bpf_raw_tp_link_attach(prog, NULL); else if (prog->expected_attach_type == BPF_TRACE_ITER) ret = bpf_iter_link_attach(attr, uattr, prog); + else if (prog->expected_attach_type == BPF_LSM_CGROUP) + ret = cgroup_bpf_link_attach(attr, prog); else ret = bpf_tracing_prog_attach(prog, attr->link_create.target_fd, diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 93c7675f0c9e..6cd226584c33 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -11,6 +11,8 @@ #include <linux/rcupdate_wait.h> #include <linux/module.h> #include <linux/static_call.h> +#include <linux/bpf_verifier.h> +#include <linux/bpf_lsm.h> /* dummy _ops. The verifier will operate on target program's ops. */ const struct bpf_verifier_ops bpf_extension_verifier_ops = { @@ -410,7 +412,7 @@ static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(struct bpf_prog *prog) } } -int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) +static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) { enum bpf_tramp_prog_type kind; struct bpf_tramp_link *link_exiting; @@ -418,44 +420,33 @@ int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline int cnt = 0, i; kind = bpf_attach_type_to_tramp(link->link.prog); - mutex_lock(&tr->mutex); - if (tr->extension_prog) { + if (tr->extension_prog) /* cannot attach fentry/fexit if extension prog is attached. * cannot overwrite extension prog either. */ - err = -EBUSY; - goto out; - } + return -EBUSY; for (i = 0; i < BPF_TRAMP_MAX; i++) cnt += tr->progs_cnt[i]; if (kind == BPF_TRAMP_REPLACE) { /* Cannot attach extension if fentry/fexit are in use. */ - if (cnt) { - err = -EBUSY; - goto out; - } + if (cnt) + return -EBUSY; tr->extension_prog = link->link.prog; - err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL, - link->link.prog->bpf_func); - goto out; - } - if (cnt >= BPF_MAX_TRAMP_LINKS) { - err = -E2BIG; - goto out; + return bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL, + link->link.prog->bpf_func); } - if (!hlist_unhashed(&link->tramp_hlist)) { + if (cnt >= BPF_MAX_TRAMP_LINKS) + return -E2BIG; + if (!hlist_unhashed(&link->tramp_hlist)) /* prog already linked */ - err = -EBUSY; - goto out; - } + return -EBUSY; hlist_for_each_entry(link_exiting, &tr->progs_hlist[kind], tramp_hlist) { if (link_exiting->link.prog != link->link.prog) continue; /* prog already linked */ - err = -EBUSY; - goto out; + return -EBUSY; } hlist_add_head(&link->tramp_hlist, &tr->progs_hlist[kind]); @@ -465,34 +456,220 @@ int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline hlist_del_init(&link->tramp_hlist); tr->progs_cnt[kind]--; } -out: + return err; +} + +int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) +{ + int err; + + mutex_lock(&tr->mutex); + err = __bpf_trampoline_link_prog(link, tr); mutex_unlock(&tr->mutex); return err; } -/* bpf_trampoline_unlink_prog() should never fail. */ -int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) +static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) { enum bpf_tramp_prog_type kind; int err; kind = bpf_attach_type_to_tramp(link->link.prog); - mutex_lock(&tr->mutex); if (kind == BPF_TRAMP_REPLACE) { WARN_ON_ONCE(!tr->extension_prog); err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, tr->extension_prog->bpf_func, NULL); tr->extension_prog = NULL; - goto out; + return err; } hlist_del_init(&link->tramp_hlist); tr->progs_cnt[kind]--; - err = bpf_trampoline_update(tr); -out: + return bpf_trampoline_update(tr); +} + +/* bpf_trampoline_unlink_prog() should never fail. */ +int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) +{ + int err; + + mutex_lock(&tr->mutex); + err = __bpf_trampoline_unlink_prog(link, tr); + mutex_unlock(&tr->mutex); + return err; +} + +#if defined(CONFIG_BPF_JIT) && defined(CONFIG_BPF_SYSCALL) +static void bpf_shim_tramp_link_release(struct bpf_link *link) +{ + struct bpf_shim_tramp_link *shim_link = + container_of(link, struct bpf_shim_tramp_link, link.link); + + /* paired with 'shim_link->trampoline = tr' in bpf_trampoline_link_cgroup_shim */ + if (!shim_link->trampoline) + return; + + WARN_ON_ONCE(bpf_trampoline_unlink_prog(&shim_link->link, shim_link->trampoline)); + bpf_trampoline_put(shim_link->trampoline); +} + +static void bpf_shim_tramp_link_dealloc(struct bpf_link *link) +{ + struct bpf_shim_tramp_link *shim_link = + container_of(link, struct bpf_shim_tramp_link, link.link); + + kfree(shim_link); +} + +static const struct bpf_link_ops bpf_shim_tramp_link_lops = { + .release = bpf_shim_tramp_link_release, + .dealloc = bpf_shim_tramp_link_dealloc, +}; + +static struct bpf_shim_tramp_link *cgroup_shim_alloc(const struct bpf_prog *prog, + bpf_func_t bpf_func, + int cgroup_atype) +{ + struct bpf_shim_tramp_link *shim_link = NULL; + struct bpf_prog *p; + + shim_link = kzalloc(sizeof(*shim_link), GFP_USER); + if (!shim_link) + return NULL; + + p = bpf_prog_alloc(1, 0); + if (!p) { + kfree(shim_link); + return NULL; + } + + p->jited = false; + p->bpf_func = bpf_func; + + p->aux->cgroup_atype = cgroup_atype; + p->aux->attach_func_proto = prog->aux->attach_func_proto; + p->aux->attach_btf_id = prog->aux->attach_btf_id; + p->aux->attach_btf = prog->aux->attach_btf; + btf_get(p->aux->attach_btf); + p->type = BPF_PROG_TYPE_LSM; + p->expected_attach_type = BPF_LSM_MAC; + bpf_prog_inc(p); + bpf_link_init(&shim_link->link.link, BPF_LINK_TYPE_UNSPEC, + &bpf_shim_tramp_link_lops, p); + bpf_cgroup_atype_get(p->aux->attach_btf_id, cgroup_atype); + + return shim_link; +} + +static struct bpf_shim_tramp_link *cgroup_shim_find(struct bpf_trampoline *tr, + bpf_func_t bpf_func) +{ + struct bpf_tramp_link *link; + int kind; + + for (kind = 0; kind < BPF_TRAMP_MAX; kind++) { + hlist_for_each_entry(link, &tr->progs_hlist[kind], tramp_hlist) { + struct bpf_prog *p = link->link.prog; + + if (p->bpf_func == bpf_func) + return container_of(link, struct bpf_shim_tramp_link, link); + } + } + + return NULL; +} + +int bpf_trampoline_link_cgroup_shim(struct bpf_prog *prog, + int cgroup_atype) +{ + struct bpf_shim_tramp_link *shim_link = NULL; + struct bpf_attach_target_info tgt_info = {}; + struct bpf_trampoline *tr; + bpf_func_t bpf_func; + u64 key; + int err; + + err = bpf_check_attach_target(NULL, prog, NULL, + prog->aux->attach_btf_id, + &tgt_info); + if (err) + return err; + + key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, + prog->aux->attach_btf_id); + + bpf_lsm_find_cgroup_shim(prog, &bpf_func); + tr = bpf_trampoline_get(key, &tgt_info); + if (!tr) + return -ENOMEM; + + mutex_lock(&tr->mutex); + + shim_link = cgroup_shim_find(tr, bpf_func); + if (shim_link) { + /* Reusing existing shim attached by the other program. */ + bpf_link_inc(&shim_link->link.link); + + mutex_unlock(&tr->mutex); + bpf_trampoline_put(tr); /* bpf_trampoline_get above */ + return 0; + } + + /* Allocate and install new shim. */ + + shim_link = cgroup_shim_alloc(prog, bpf_func, cgroup_atype); + if (!shim_link) { + err = -ENOMEM; + goto err; + } + + err = __bpf_trampoline_link_prog(&shim_link->link, tr); + if (err) + goto err; + + shim_link->trampoline = tr; + /* note, we're still holding tr refcnt from above */ + mutex_unlock(&tr->mutex); + + return 0; +err: + mutex_unlock(&tr->mutex); + + if (shim_link) + bpf_link_put(&shim_link->link.link); + + /* have to release tr while _not_ holding its mutex */ + bpf_trampoline_put(tr); /* bpf_trampoline_get above */ + return err; } +void bpf_trampoline_unlink_cgroup_shim(struct bpf_prog *prog) +{ + struct bpf_shim_tramp_link *shim_link = NULL; + struct bpf_trampoline *tr; + bpf_func_t bpf_func; + u64 key; + + key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, + prog->aux->attach_btf_id); + + bpf_lsm_find_cgroup_shim(prog, &bpf_func); + tr = bpf_trampoline_lookup(key); + if (WARN_ON_ONCE(!tr)) + return; + + mutex_lock(&tr->mutex); + shim_link = cgroup_shim_find(tr, bpf_func); + mutex_unlock(&tr->mutex); + + if (shim_link) + bpf_link_put(&shim_link->link.link); + + bpf_trampoline_put(tr); /* bpf_trampoline_lookup above */ +} +#endif + struct bpf_trampoline *bpf_trampoline_get(u64 key, struct bpf_attach_target_info *tgt_info) { @@ -625,6 +802,31 @@ void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start, struct bpf_tramp_ rcu_read_unlock(); } +u64 notrace __bpf_prog_enter_lsm_cgroup(struct bpf_prog *prog, + struct bpf_tramp_run_ctx *run_ctx) + __acquires(RCU) +{ + /* Runtime stats are exported via actual BPF_LSM_CGROUP + * programs, not the shims. + */ + rcu_read_lock(); + migrate_disable(); + + run_ctx->saved_run_ctx = bpf_set_run_ctx(&run_ctx->run_ctx); + + return NO_START_TIME; +} + +void notrace __bpf_prog_exit_lsm_cgroup(struct bpf_prog *prog, u64 start, + struct bpf_tramp_run_ctx *run_ctx) + __releases(RCU) +{ + bpf_reset_run_ctx(run_ctx->saved_run_ctx); + + migrate_enable(); + rcu_read_unlock(); +} + u64 notrace __bpf_prog_enter_sleepable(struct bpf_prog *prog, struct bpf_tramp_run_ctx *run_ctx) { rcu_read_lock_trace(); diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 4938477912cd..df3ec6b05f05 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7322,6 +7322,18 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn reg_type_str(env, regs[BPF_REG_1].type)); return -EACCES; } + break; + case BPF_FUNC_set_retval: + if (env->prog->expected_attach_type == BPF_LSM_CGROUP) { + if (!env->prog->aux->attach_func_proto->type) { + /* Make sure programs that attach to void + * hooks don't try to modify return value. + */ + verbose(env, "BPF_LSM_CGROUP that attach to void LSM hooks can't modify return value!\n"); + return -EINVAL; + } + } + break; } if (err) @@ -10527,6 +10539,22 @@ static int check_return_code(struct bpf_verifier_env *env) case BPF_PROG_TYPE_SK_LOOKUP: range = tnum_range(SK_DROP, SK_PASS); break; + + case BPF_PROG_TYPE_LSM: + if (env->prog->expected_attach_type != BPF_LSM_CGROUP) { + /* Regular BPF_PROG_TYPE_LSM programs can return + * any value. + */ + return 0; + } + if (!env->prog->aux->attach_func_proto->type) { + /* Make sure programs that attach to void + * hooks don't try to modify return value. + */ + range = tnum_range(1, 1); + } + break; + case BPF_PROG_TYPE_EXT: /* freplace program can return anything as its return value * depends on the to-be-replaced kernel func or bpf program. @@ -10543,6 +10571,9 @@ static int check_return_code(struct bpf_verifier_env *env) if (!tnum_in(range, reg->var_off)) { verbose_invalid_scalar(env, reg, &range, "program exit", "R0"); + if (prog->expected_attach_type == BPF_LSM_CGROUP && + !prog->aux->attach_func_proto->type) + verbose(env, "Note, BPF_LSM_CGROUP that attach to void LSM hooks can't modify return value!\n"); return -EINVAL; } @@ -14902,6 +14933,7 @@ int bpf_check_attach_target(struct bpf_verifier_log *log, fallthrough; case BPF_MODIFY_RETURN: case BPF_LSM_MAC: + case BPF_LSM_CGROUP: case BPF_TRACE_FENTRY: case BPF_TRACE_FEXIT: if (!btf_type_is_func(t)) { diff --git a/net/core/filter.c b/net/core/filter.c index 151aa4756bd6..c6941ab0eb52 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5012,8 +5012,8 @@ static const struct bpf_func_proto bpf_get_socket_uid_proto = { .arg1_type = ARG_PTR_TO_CTX, }; -static int _bpf_setsockopt(struct sock *sk, int level, int optname, - char *optval, int optlen) +static int __bpf_setsockopt(struct sock *sk, int level, int optname, + char *optval, int optlen) { char devname[IFNAMSIZ]; int val, valbool; @@ -5024,8 +5024,6 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, if (!sk_fullsock(sk)) return -EINVAL; - sock_owned_by_me(sk); - if (level == SOL_SOCKET) { if (optlen != sizeof(int) && optname != SO_BINDTODEVICE) return -EINVAL; @@ -5258,14 +5256,20 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, return ret; } -static int _bpf_getsockopt(struct sock *sk, int level, int optname, +static int _bpf_setsockopt(struct sock *sk, int level, int optname, char *optval, int optlen) { + if (sk_fullsock(sk)) + sock_owned_by_me(sk); + return __bpf_setsockopt(sk, level, optname, optval, optlen); +} + +static int __bpf_getsockopt(struct sock *sk, int level, int optname, + char *optval, int optlen) +{ if (!sk_fullsock(sk)) goto err_clear; - sock_owned_by_me(sk); - if (level == SOL_SOCKET) { if (optlen != sizeof(int)) goto err_clear; @@ -5360,6 +5364,14 @@ err_clear: return -EINVAL; } +static int _bpf_getsockopt(struct sock *sk, int level, int optname, + char *optval, int optlen) +{ + if (sk_fullsock(sk)) + sock_owned_by_me(sk); + return __bpf_getsockopt(sk, level, optname, optval, optlen); +} + BPF_CALL_5(bpf_sk_setsockopt, struct sock *, sk, int, level, int, optname, char *, optval, int, optlen) { @@ -5400,6 +5412,40 @@ const struct bpf_func_proto bpf_sk_getsockopt_proto = { .arg5_type = ARG_CONST_SIZE, }; +BPF_CALL_5(bpf_unlocked_sk_setsockopt, struct sock *, sk, int, level, + int, optname, char *, optval, int, optlen) +{ + return __bpf_setsockopt(sk, level, optname, optval, optlen); +} + +const struct bpf_func_proto bpf_unlocked_sk_setsockopt_proto = { + .func = bpf_unlocked_sk_setsockopt, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY, + .arg5_type = ARG_CONST_SIZE, +}; + +BPF_CALL_5(bpf_unlocked_sk_getsockopt, struct sock *, sk, int, level, + int, optname, char *, optval, int, optlen) +{ + return __bpf_getsockopt(sk, level, optname, optval, optlen); +} + +const struct bpf_func_proto bpf_unlocked_sk_getsockopt_proto = { + .func = bpf_unlocked_sk_getsockopt, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_PTR_TO_UNINIT_MEM, + .arg5_type = ARG_CONST_SIZE, +}; + BPF_CALL_5(bpf_sock_addr_setsockopt, struct bpf_sock_addr_kern *, ctx, int, level, int, optname, char *, optval, int, optlen) { diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c index 42421fe47a58..cced668fb2a3 100644 --- a/tools/bpf/bpftool/cgroup.c +++ b/tools/bpf/bpftool/cgroup.c @@ -15,6 +15,7 @@ #include <unistd.h> #include <bpf/bpf.h> +#include <bpf/btf.h> #include "main.h" @@ -36,6 +37,8 @@ " cgroup_inet_sock_release }" static unsigned int query_flags; +static struct btf *btf_vmlinux; +static __u32 btf_vmlinux_id; static enum bpf_attach_type parse_attach_type(const char *str) { @@ -64,11 +67,38 @@ static enum bpf_attach_type parse_attach_type(const char *str) return __MAX_BPF_ATTACH_TYPE; } +static void guess_vmlinux_btf_id(__u32 attach_btf_obj_id) +{ + struct bpf_btf_info btf_info = {}; + __u32 btf_len = sizeof(btf_info); + char name[16] = {}; + int err; + int fd; + + btf_info.name = ptr_to_u64(name); + btf_info.name_len = sizeof(name); + + fd = bpf_btf_get_fd_by_id(attach_btf_obj_id); + if (fd < 0) + return; + + err = bpf_obj_get_info_by_fd(fd, &btf_info, &btf_len); + if (err) + goto out; + + if (btf_info.kernel_btf && strncmp(name, "vmlinux", sizeof(name)) == 0) + btf_vmlinux_id = btf_info.id; + +out: + close(fd); +} + static int show_bpf_prog(int id, enum bpf_attach_type attach_type, const char *attach_flags_str, int level) { char prog_name[MAX_PROG_FULL_NAME]; + const char *attach_btf_name = NULL; struct bpf_prog_info info = {}; const char *attach_type_str; __u32 info_len = sizeof(info); @@ -84,6 +114,20 @@ static int show_bpf_prog(int id, enum bpf_attach_type attach_type, } attach_type_str = libbpf_bpf_attach_type_str(attach_type); + + if (btf_vmlinux) { + if (!btf_vmlinux_id) + guess_vmlinux_btf_id(info.attach_btf_obj_id); + + if (btf_vmlinux_id == info.attach_btf_obj_id && + info.attach_btf_id < btf__type_cnt(btf_vmlinux)) { + const struct btf_type *t = + btf__type_by_id(btf_vmlinux, info.attach_btf_id); + attach_btf_name = + btf__name_by_offset(btf_vmlinux, t->name_off); + } + } + get_prog_full_name(&info, prog_fd, prog_name, sizeof(prog_name)); if (json_output) { jsonw_start_object(json_wtr); @@ -95,6 +139,10 @@ static int show_bpf_prog(int id, enum bpf_attach_type attach_type, jsonw_string_field(json_wtr, "attach_flags", attach_flags_str); jsonw_string_field(json_wtr, "name", prog_name); + if (attach_btf_name) + jsonw_string_field(json_wtr, "attach_btf_name", attach_btf_name); + jsonw_uint_field(json_wtr, "attach_btf_obj_id", info.attach_btf_obj_id); + jsonw_uint_field(json_wtr, "attach_btf_id", info.attach_btf_id); jsonw_end_object(json_wtr); } else { printf("%s%-8u ", level ? " " : "", info.id); @@ -102,7 +150,13 @@ static int show_bpf_prog(int id, enum bpf_attach_type attach_type, printf("%-15s", attach_type_str); else printf("type %-10u", attach_type); - printf(" %-15s %-15s\n", attach_flags_str, prog_name); + printf(" %-15s %-15s", attach_flags_str, prog_name); + if (attach_btf_name) + printf(" %-15s", attach_btf_name); + else if (info.attach_btf_id) + printf(" attach_btf_obj_id=%d attach_btf_id=%d", + info.attach_btf_obj_id, info.attach_btf_id); + printf("\n"); } close(prog_fd); @@ -144,40 +198,49 @@ static int cgroup_has_attached_progs(int cgroup_fd) static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type, int level) { + LIBBPF_OPTS(bpf_prog_query_opts, p); + __u32 prog_attach_flags[1024] = {0}; const char *attach_flags_str; __u32 prog_ids[1024] = {0}; - __u32 prog_cnt, iter; - __u32 attach_flags; char buf[32]; + __u32 iter; int ret; - prog_cnt = ARRAY_SIZE(prog_ids); - ret = bpf_prog_query(cgroup_fd, type, query_flags, &attach_flags, - prog_ids, &prog_cnt); + p.query_flags = query_flags; + p.prog_cnt = ARRAY_SIZE(prog_ids); + p.prog_ids = prog_ids; + p.prog_attach_flags = prog_attach_flags; + + ret = bpf_prog_query_opts(cgroup_fd, type, &p); if (ret) return ret; - if (prog_cnt == 0) + if (p.prog_cnt == 0) return 0; - switch (attach_flags) { - case BPF_F_ALLOW_MULTI: - attach_flags_str = "multi"; - break; - case BPF_F_ALLOW_OVERRIDE: - attach_flags_str = "override"; - break; - case 0: - attach_flags_str = ""; - break; - default: - snprintf(buf, sizeof(buf), "unknown(%x)", attach_flags); - attach_flags_str = buf; - } + for (iter = 0; iter < p.prog_cnt; iter++) { + __u32 attach_flags; + + attach_flags = prog_attach_flags[iter] ?: p.attach_flags; + + switch (attach_flags) { + case BPF_F_ALLOW_MULTI: + attach_flags_str = "multi"; + break; + case BPF_F_ALLOW_OVERRIDE: + attach_flags_str = "override"; + break; + case 0: + attach_flags_str = ""; + break; + default: + snprintf(buf, sizeof(buf), "unknown(%x)", attach_flags); + attach_flags_str = buf; + } - for (iter = 0; iter < prog_cnt; iter++) show_bpf_prog(prog_ids[iter], type, attach_flags_str, level); + } return 0; } @@ -233,6 +296,7 @@ static int do_show(int argc, char **argv) printf("%-8s %-15s %-15s %-15s\n", "ID", "AttachType", "AttachFlags", "Name"); + btf_vmlinux = libbpf_find_kernel_btf(); for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) { /* * Not all attach types may be supported, so it's expected, @@ -296,6 +360,7 @@ static int do_show_tree_fn(const char *fpath, const struct stat *sb, printf("%s\n", fpath); } + btf_vmlinux = libbpf_find_kernel_btf(); for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) show_attached_bpf_progs(cgroup_fd, type, ftw->level); diff --git a/tools/include/linux/btf_ids.h b/tools/include/linux/btf_ids.h index 57890b357f85..71e54b1e3796 100644 --- a/tools/include/linux/btf_ids.h +++ b/tools/include/linux/btf_ids.h @@ -73,7 +73,7 @@ asm( \ __BTF_ID_LIST(name, local) \ extern u32 name[]; -#define BTF_ID_LIST_GLOBAL(name) \ +#define BTF_ID_LIST_GLOBAL(name, n) \ __BTF_ID_LIST(name, globl) /* The BTF_ID_LIST_SINGLE macro defines a BTF_ID_LIST with @@ -82,6 +82,9 @@ __BTF_ID_LIST(name, globl) #define BTF_ID_LIST_SINGLE(name, prefix, typename) \ BTF_ID_LIST(name) \ BTF_ID(prefix, typename) +#define BTF_ID_LIST_GLOBAL_SINGLE(name, prefix, typename) \ + BTF_ID_LIST_GLOBAL(name, 1) \ + BTF_ID(prefix, typename) /* * The BTF_ID_UNUSED macro defines 4 zero bytes. @@ -143,13 +146,14 @@ extern struct btf_id_set name; #else -#define BTF_ID_LIST(name) static u32 name[5]; +#define BTF_ID_LIST(name) static u32 __maybe_unused name[5]; #define BTF_ID(prefix, name) #define BTF_ID_UNUSED -#define BTF_ID_LIST_GLOBAL(name) u32 name[1]; -#define BTF_ID_LIST_SINGLE(name, prefix, typename) static u32 name[1]; -#define BTF_SET_START(name) static struct btf_id_set name = { 0 }; -#define BTF_SET_START_GLOBAL(name) static struct btf_id_set name = { 0 }; +#define BTF_ID_LIST_GLOBAL(name, n) u32 __maybe_unused name[n]; +#define BTF_ID_LIST_SINGLE(name, prefix, typename) static u32 __maybe_unused name[1]; +#define BTF_ID_LIST_GLOBAL_SINGLE(name, prefix, typename) u32 __maybe_unused name[1]; +#define BTF_SET_START(name) static struct btf_id_set __maybe_unused name = { 0 }; +#define BTF_SET_START_GLOBAL(name) static struct btf_id_set __maybe_unused name = { 0 }; #define BTF_SET_END(name) #endif /* CONFIG_DEBUG_INFO_BTF */ @@ -172,7 +176,10 @@ extern struct btf_id_set name; BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_TW, tcp_timewait_sock) \ BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP6, tcp6_sock) \ BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, udp_sock) \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock) + BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_UNIX, unix_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_MPTCP, mptcp_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCKET, socket) enum { #define BTF_SOCK_TYPE(name, str) name, @@ -184,4 +191,18 @@ MAX_BTF_SOCK_TYPE, extern u32 btf_sock_ids[]; #endif +#define BTF_TRACING_TYPE_xxx \ + BTF_TRACING_TYPE(BTF_TRACING_TYPE_TASK, task_struct) \ + BTF_TRACING_TYPE(BTF_TRACING_TYPE_FILE, file) \ + BTF_TRACING_TYPE(BTF_TRACING_TYPE_VMA, vm_area_struct) + +enum { +#define BTF_TRACING_TYPE(name, type) name, +BTF_TRACING_TYPE_xxx +#undef BTF_TRACING_TYPE +MAX_BTF_TRACING_TYPE, +}; + +extern u32 btf_tracing_ids[]; + #endif diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index e81362891596..ad9e7311c4cf 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -998,6 +998,7 @@ enum bpf_attach_type { BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, BPF_PERF_EVENT, BPF_TRACE_KPROBE_MULTI, + BPF_LSM_CGROUP, __MAX_BPF_ATTACH_TYPE }; @@ -1431,6 +1432,7 @@ union bpf_attr { __u32 attach_flags; __aligned_u64 prog_ids; __u32 prog_cnt; + __aligned_u64 prog_attach_flags; /* output: per-program attach_flags */ } query; struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */ @@ -6075,6 +6077,8 @@ struct bpf_prog_info { __u64 run_cnt; __u64 recursion_misses; __u32 verified_insns; + __u32 attach_btf_obj_id; + __u32 attach_btf_id; } __attribute__((aligned(8))); struct bpf_map_info { diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 6d848b02c1e0..5eb0df90eb2b 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -795,24 +795,48 @@ int bpf_iter_create(int link_fd) return libbpf_err_errno(fd); } -int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, - __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt) +int bpf_prog_query_opts(int target_fd, + enum bpf_attach_type type, + struct bpf_prog_query_opts *opts) { union bpf_attr attr; int ret; + if (!OPTS_VALID(opts, bpf_prog_query_opts)) + return libbpf_err(-EINVAL); + memset(&attr, 0, sizeof(attr)); + attr.query.target_fd = target_fd; attr.query.attach_type = type; - attr.query.query_flags = query_flags; - attr.query.prog_cnt = *prog_cnt; - attr.query.prog_ids = ptr_to_u64(prog_ids); + attr.query.query_flags = OPTS_GET(opts, query_flags, 0); + attr.query.prog_cnt = OPTS_GET(opts, prog_cnt, 0); + attr.query.prog_ids = ptr_to_u64(OPTS_GET(opts, prog_ids, NULL)); + attr.query.prog_attach_flags = ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL)); ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr)); + OPTS_SET(opts, attach_flags, attr.query.attach_flags); + OPTS_SET(opts, prog_cnt, attr.query.prog_cnt); + + return libbpf_err_errno(ret); +} + +int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, + __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt) +{ + LIBBPF_OPTS(bpf_prog_query_opts, opts); + int ret; + + opts.query_flags = query_flags; + opts.prog_ids = prog_ids; + opts.prog_cnt = *prog_cnt; + + ret = bpf_prog_query_opts(target_fd, type, &opts); + if (attach_flags) - *attach_flags = attr.query.attach_flags; - *prog_cnt = attr.query.prog_cnt; + *attach_flags = opts.attach_flags; + *prog_cnt = opts.prog_cnt; return libbpf_err_errno(ret); } diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index af7baf5da74d..88a7cc4bd76f 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -359,9 +359,24 @@ LIBBPF_API int bpf_map_get_fd_by_id(__u32 id); LIBBPF_API int bpf_btf_get_fd_by_id(__u32 id); LIBBPF_API int bpf_link_get_fd_by_id(__u32 id); LIBBPF_API int bpf_obj_get_info_by_fd(int bpf_fd, void *info, __u32 *info_len); + +struct bpf_prog_query_opts { + size_t sz; /* size of this struct for forward/backward compatibility */ + __u32 query_flags; + __u32 attach_flags; /* output argument */ + __u32 *prog_ids; + __u32 prog_cnt; /* input+output argument */ + __u32 *prog_attach_flags; +}; +#define bpf_prog_query_opts__last_field prog_attach_flags + +LIBBPF_API int bpf_prog_query_opts(int target_fd, + enum bpf_attach_type type, + struct bpf_prog_query_opts *opts); LIBBPF_API int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt); + LIBBPF_API int bpf_raw_tracepoint_open(const char *name, int prog_fd); LIBBPF_API int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type, diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index e994797bcd48..8a45a84eb9b2 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -106,6 +106,7 @@ static const char * const attach_type_name[] = { [BPF_TRACE_FEXIT] = "trace_fexit", [BPF_MODIFY_RETURN] = "modify_return", [BPF_LSM_MAC] = "lsm_mac", + [BPF_LSM_CGROUP] = "lsm_cgroup", [BPF_SK_LOOKUP] = "sk_lookup", [BPF_TRACE_ITER] = "trace_iter", [BPF_XDP_DEVMAP] = "xdp_devmap", @@ -8414,6 +8415,7 @@ static const struct bpf_sec_def section_defs[] = { SEC_DEF("freplace+", EXT, 0, SEC_ATTACH_BTF, attach_trace), SEC_DEF("lsm+", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF, attach_lsm), SEC_DEF("lsm.s+", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm), + SEC_DEF("lsm_cgroup+", LSM, BPF_LSM_CGROUP, SEC_ATTACH_BTF), SEC_DEF("iter+", TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF, attach_iter), SEC_DEF("iter.s+", TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_iter), SEC_DEF("syscall", SYSCALL, 0, SEC_SLEEPABLE), @@ -8851,6 +8853,7 @@ void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type, *kind = BTF_KIND_TYPEDEF; break; case BPF_LSM_MAC: + case BPF_LSM_CGROUP: *prefix = BTF_LSM_PREFIX; *kind = BTF_KIND_FUNC; break; diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 43c6697a6d27..94b589ecfeaa 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -355,6 +355,7 @@ LIBBPF_0.8.0 { LIBBPF_1.0.0 { global: + bpf_prog_query_opts; btf__add_enum64; btf__add_enum64_value; libbpf_bpf_attach_type_str; diff --git a/tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c b/tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c new file mode 100644 index 000000000000..d40810a742fa --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c @@ -0,0 +1,293 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <sys/types.h> +#include <sys/socket.h> +#include <test_progs.h> +#include <bpf/btf.h> + +#include "lsm_cgroup.skel.h" +#include "cgroup_helpers.h" +#include "network_helpers.h" + +static struct btf *btf; + +static __u32 query_prog_cnt(int cgroup_fd, const char *attach_func) +{ + LIBBPF_OPTS(bpf_prog_query_opts, p); + int cnt = 0; + int i; + + ASSERT_OK(bpf_prog_query_opts(cgroup_fd, BPF_LSM_CGROUP, &p), "prog_query"); + + if (!attach_func) + return p.prog_cnt; + + /* When attach_func is provided, count the number of progs that + * attach to the given symbol. + */ + + if (!btf) + btf = btf__load_vmlinux_btf(); + if (!ASSERT_OK(libbpf_get_error(btf), "btf_vmlinux")) + return -1; + + p.prog_ids = malloc(sizeof(u32) * p.prog_cnt); + p.prog_attach_flags = malloc(sizeof(u32) * p.prog_cnt); + ASSERT_OK(bpf_prog_query_opts(cgroup_fd, BPF_LSM_CGROUP, &p), "prog_query"); + + for (i = 0; i < p.prog_cnt; i++) { + struct bpf_prog_info info = {}; + __u32 info_len = sizeof(info); + int fd; + + fd = bpf_prog_get_fd_by_id(p.prog_ids[i]); + ASSERT_GE(fd, 0, "prog_get_fd_by_id"); + ASSERT_OK(bpf_obj_get_info_by_fd(fd, &info, &info_len), "prog_info_by_fd"); + close(fd); + + if (info.attach_btf_id == + btf__find_by_name_kind(btf, attach_func, BTF_KIND_FUNC)) + cnt++; + } + + free(p.prog_ids); + free(p.prog_attach_flags); + + return cnt; +} + +static void test_lsm_cgroup_functional(void) +{ + DECLARE_LIBBPF_OPTS(bpf_prog_attach_opts, attach_opts); + DECLARE_LIBBPF_OPTS(bpf_link_update_opts, update_opts); + int cgroup_fd = -1, cgroup_fd2 = -1, cgroup_fd3 = -1; + int listen_fd, client_fd, accepted_fd; + struct lsm_cgroup *skel = NULL; + int post_create_prog_fd2 = -1; + int post_create_prog_fd = -1; + int bind_link_fd2 = -1; + int bind_prog_fd2 = -1; + int alloc_prog_fd = -1; + int bind_prog_fd = -1; + int bind_link_fd = -1; + int clone_prog_fd = -1; + int err, fd, prio; + socklen_t socklen; + + cgroup_fd3 = test__join_cgroup("/sock_policy_empty"); + if (!ASSERT_GE(cgroup_fd3, 0, "create empty cgroup")) + goto close_cgroup; + + cgroup_fd2 = test__join_cgroup("/sock_policy_reuse"); + if (!ASSERT_GE(cgroup_fd2, 0, "create cgroup for reuse")) + goto close_cgroup; + + cgroup_fd = test__join_cgroup("/sock_policy"); + if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup")) + goto close_cgroup; + + skel = lsm_cgroup__open_and_load(); + if (!ASSERT_OK_PTR(skel, "open_and_load")) + goto close_cgroup; + + post_create_prog_fd = bpf_program__fd(skel->progs.socket_post_create); + post_create_prog_fd2 = bpf_program__fd(skel->progs.socket_post_create2); + bind_prog_fd = bpf_program__fd(skel->progs.socket_bind); + bind_prog_fd2 = bpf_program__fd(skel->progs.socket_bind2); + alloc_prog_fd = bpf_program__fd(skel->progs.socket_alloc); + clone_prog_fd = bpf_program__fd(skel->progs.socket_clone); + + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_sk_alloc_security"), 0, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 0, "total prog count"); + err = bpf_prog_attach(alloc_prog_fd, cgroup_fd, BPF_LSM_CGROUP, 0); + if (!ASSERT_OK(err, "attach alloc_prog_fd")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_sk_alloc_security"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 1, "total prog count"); + + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_inet_csk_clone"), 0, "prog count"); + err = bpf_prog_attach(clone_prog_fd, cgroup_fd, BPF_LSM_CGROUP, 0); + if (!ASSERT_OK(err, "attach clone_prog_fd")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_inet_csk_clone"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 2, "total prog count"); + + /* Make sure replacing works. */ + + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_post_create"), 0, "prog count"); + err = bpf_prog_attach(post_create_prog_fd, cgroup_fd, + BPF_LSM_CGROUP, 0); + if (!ASSERT_OK(err, "attach post_create_prog_fd")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_post_create"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 3, "total prog count"); + + attach_opts.replace_prog_fd = post_create_prog_fd; + err = bpf_prog_attach_opts(post_create_prog_fd2, cgroup_fd, + BPF_LSM_CGROUP, &attach_opts); + if (!ASSERT_OK(err, "prog replace post_create_prog_fd")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_post_create"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 3, "total prog count"); + + /* Try the same attach/replace via link API. */ + + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_bind"), 0, "prog count"); + bind_link_fd = bpf_link_create(bind_prog_fd, cgroup_fd, + BPF_LSM_CGROUP, NULL); + if (!ASSERT_GE(bind_link_fd, 0, "link create bind_prog_fd")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_bind"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 4, "total prog count"); + + update_opts.old_prog_fd = bind_prog_fd; + update_opts.flags = BPF_F_REPLACE; + + err = bpf_link_update(bind_link_fd, bind_prog_fd2, &update_opts); + if (!ASSERT_OK(err, "link update bind_prog_fd")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_bind"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 4, "total prog count"); + + /* Attach another instance of bind program to another cgroup. + * This should trigger the reuse of the trampoline shim (two + * programs attaching to the same btf_id). + */ + + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_bind"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd2, "bpf_lsm_socket_bind"), 0, "prog count"); + bind_link_fd2 = bpf_link_create(bind_prog_fd2, cgroup_fd2, + BPF_LSM_CGROUP, NULL); + if (!ASSERT_GE(bind_link_fd2, 0, "link create bind_prog_fd2")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd2, "bpf_lsm_socket_bind"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 4, "total prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd2, NULL), 1, "total prog count"); + + /* AF_UNIX is prohibited. */ + + fd = socket(AF_UNIX, SOCK_STREAM, 0); + ASSERT_LT(fd, 0, "socket(AF_UNIX)"); + close(fd); + + /* AF_INET6 gets default policy (sk_priority). */ + + fd = socket(AF_INET6, SOCK_STREAM, 0); + if (!ASSERT_GE(fd, 0, "socket(SOCK_STREAM)")) + goto detach_cgroup; + + prio = 0; + socklen = sizeof(prio); + ASSERT_GE(getsockopt(fd, SOL_SOCKET, SO_PRIORITY, &prio, &socklen), 0, + "getsockopt"); + ASSERT_EQ(prio, 123, "sk_priority"); + + close(fd); + + /* TX-only AF_PACKET is allowed. */ + + ASSERT_LT(socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL)), 0, + "socket(AF_PACKET, ..., ETH_P_ALL)"); + + fd = socket(AF_PACKET, SOCK_RAW, 0); + ASSERT_GE(fd, 0, "socket(AF_PACKET, ..., 0)"); + + /* TX-only AF_PACKET can not be rebound. */ + + struct sockaddr_ll sa = { + .sll_family = AF_PACKET, + .sll_protocol = htons(ETH_P_ALL), + }; + ASSERT_LT(bind(fd, (struct sockaddr *)&sa, sizeof(sa)), 0, + "bind(ETH_P_ALL)"); + + close(fd); + + /* Trigger passive open. */ + + listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0); + ASSERT_GE(listen_fd, 0, "start_server"); + client_fd = connect_to_fd(listen_fd, 0); + ASSERT_GE(client_fd, 0, "connect_to_fd"); + accepted_fd = accept(listen_fd, NULL, NULL); + ASSERT_GE(accepted_fd, 0, "accept"); + + prio = 0; + socklen = sizeof(prio); + ASSERT_GE(getsockopt(accepted_fd, SOL_SOCKET, SO_PRIORITY, &prio, &socklen), 0, + "getsockopt"); + ASSERT_EQ(prio, 234, "sk_priority"); + + /* These are replaced and never called. */ + ASSERT_EQ(skel->bss->called_socket_post_create, 0, "called_create"); + ASSERT_EQ(skel->bss->called_socket_bind, 0, "called_bind"); + + /* AF_INET6+SOCK_STREAM + * AF_PACKET+SOCK_RAW + * listen_fd + * client_fd + * accepted_fd + */ + ASSERT_EQ(skel->bss->called_socket_post_create2, 5, "called_create2"); + + /* start_server + * bind(ETH_P_ALL) + */ + ASSERT_EQ(skel->bss->called_socket_bind2, 2, "called_bind2"); + /* Single accept(). */ + ASSERT_EQ(skel->bss->called_socket_clone, 1, "called_clone"); + + /* AF_UNIX+SOCK_STREAM (failed) + * AF_INET6+SOCK_STREAM + * AF_PACKET+SOCK_RAW (failed) + * AF_PACKET+SOCK_RAW + * listen_fd + * client_fd + * accepted_fd + */ + ASSERT_EQ(skel->bss->called_socket_alloc, 7, "called_alloc"); + + close(listen_fd); + close(client_fd); + close(accepted_fd); + + /* Make sure other cgroup doesn't trigger the programs. */ + + if (!ASSERT_OK(join_cgroup("/sock_policy_empty"), "join root cgroup")) + goto detach_cgroup; + + fd = socket(AF_INET6, SOCK_STREAM, 0); + if (!ASSERT_GE(fd, 0, "socket(SOCK_STREAM)")) + goto detach_cgroup; + + prio = 0; + socklen = sizeof(prio); + ASSERT_GE(getsockopt(fd, SOL_SOCKET, SO_PRIORITY, &prio, &socklen), 0, + "getsockopt"); + ASSERT_EQ(prio, 0, "sk_priority"); + + close(fd); + +detach_cgroup: + ASSERT_GE(bpf_prog_detach2(post_create_prog_fd2, cgroup_fd, + BPF_LSM_CGROUP), 0, "detach_create"); + close(bind_link_fd); + /* Don't close bind_link_fd2, exercise cgroup release cleanup. */ + ASSERT_GE(bpf_prog_detach2(alloc_prog_fd, cgroup_fd, + BPF_LSM_CGROUP), 0, "detach_alloc"); + ASSERT_GE(bpf_prog_detach2(clone_prog_fd, cgroup_fd, + BPF_LSM_CGROUP), 0, "detach_clone"); + +close_cgroup: + close(cgroup_fd); + close(cgroup_fd2); + close(cgroup_fd3); + lsm_cgroup__destroy(skel); +} + +void test_lsm_cgroup(void) +{ + if (test__start_subtest("functional")) + test_lsm_cgroup_functional(); + btf__free(btf); +} diff --git a/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c b/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c index f4a13d9dd5c8..c197261d02e2 100644 --- a/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c +++ b/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c @@ -44,7 +44,7 @@ BTF_ID(union, U) BTF_ID(func, func) extern __u32 test_list_global[]; -BTF_ID_LIST_GLOBAL(test_list_global) +BTF_ID_LIST_GLOBAL(test_list_global, 1) BTF_ID_UNUSED BTF_ID(typedef, S) BTF_ID(typedef, T) diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h index 1c1289ba5fc5..98dd2c4815f0 100644 --- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h +++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h @@ -8,6 +8,7 @@ #define SOL_SOCKET 1 #define SO_SNDBUF 7 #define __SO_ACCEPTCON (1 << 16) +#define SO_PRIORITY 12 #define SOL_TCP 6 #define TCP_CONGESTION 13 diff --git a/tools/testing/selftests/bpf/progs/lsm_cgroup.c b/tools/testing/selftests/bpf/progs/lsm_cgroup.c new file mode 100644 index 000000000000..89f3b1e961a8 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/lsm_cgroup.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include "bpf_tracing_net.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +char _license[] SEC("license") = "GPL"; + +#ifndef AF_PACKET +#define AF_PACKET 17 +#endif + +#ifndef AF_UNIX +#define AF_UNIX 1 +#endif + +#ifndef EPERM +#define EPERM 1 +#endif + +struct { + __uint(type, BPF_MAP_TYPE_CGROUP_STORAGE); + __type(key, __u64); + __type(value, __u64); +} cgroup_storage SEC(".maps"); + +int called_socket_post_create; +int called_socket_post_create2; +int called_socket_bind; +int called_socket_bind2; +int called_socket_alloc; +int called_socket_clone; + +static __always_inline int test_local_storage(void) +{ + __u64 *val; + + val = bpf_get_local_storage(&cgroup_storage, 0); + if (!val) + return 0; + *val += 1; + + return 1; +} + +static __always_inline int real_create(struct socket *sock, int family, + int protocol) +{ + struct sock *sk; + int prio = 123; + + /* Reject non-tx-only AF_PACKET. */ + if (family == AF_PACKET && protocol != 0) + return 0; /* EPERM */ + + sk = sock->sk; + if (!sk) + return 1; + + /* The rest of the sockets get default policy. */ + if (bpf_setsockopt(sk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; /* EPERM */ + + /* Make sure bpf_getsockopt is allowed and works. */ + prio = 0; + if (bpf_getsockopt(sk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; /* EPERM */ + if (prio != 123) + return 0; /* EPERM */ + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 0; /* EPERM */ + + return 1; +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_post_create") +int BPF_PROG(socket_post_create, struct socket *sock, int family, + int type, int protocol, int kern) +{ + called_socket_post_create++; + return real_create(sock, family, protocol); +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_post_create") +int BPF_PROG(socket_post_create2, struct socket *sock, int family, + int type, int protocol, int kern) +{ + called_socket_post_create2++; + return real_create(sock, family, protocol); +} + +static __always_inline int real_bind(struct socket *sock, + struct sockaddr *address, + int addrlen) +{ + struct sockaddr_ll sa = {}; + + if (sock->sk->__sk_common.skc_family != AF_PACKET) + return 1; + + if (sock->sk->sk_kern_sock) + return 1; + + bpf_probe_read_kernel(&sa, sizeof(sa), address); + if (sa.sll_protocol) + return 0; /* EPERM */ + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 0; /* EPERM */ + + return 1; +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_bind") +int BPF_PROG(socket_bind, struct socket *sock, struct sockaddr *address, + int addrlen) +{ + called_socket_bind++; + return real_bind(sock, address, addrlen); +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_bind") +int BPF_PROG(socket_bind2, struct socket *sock, struct sockaddr *address, + int addrlen) +{ + called_socket_bind2++; + return real_bind(sock, address, addrlen); +} + +/* __cgroup_bpf_run_lsm_current (via bpf_lsm_current_hooks) */ +SEC("lsm_cgroup/sk_alloc_security") +int BPF_PROG(socket_alloc, struct sock *sk, int family, gfp_t priority) +{ + called_socket_alloc++; + if (family == AF_UNIX) + return 0; /* EPERM */ + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 0; /* EPERM */ + + return 1; +} + +/* __cgroup_bpf_run_lsm_sock */ +SEC("lsm_cgroup/inet_csk_clone") +int BPF_PROG(socket_clone, struct sock *newsk, const struct request_sock *req) +{ + int prio = 234; + + called_socket_clone++; + + if (!newsk) + return 1; + + /* Accepted request sockets get a different priority. */ + if (bpf_setsockopt(newsk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; /* EPERM */ + + /* Make sure bpf_getsockopt is allowed and works. */ + prio = 0; + if (bpf_getsockopt(newsk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; /* EPERM */ + if (prio != 234) + return 0; /* EPERM */ + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 0; /* EPERM */ + + return 1; +} |