diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 16 | ||||
| -rw-r--r-- | net/core/filter.c | 21 |
2 files changed, 35 insertions, 2 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index d690c7dd1f1a..477b6932c3c1 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4203,6 +4203,22 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) continue; } + if (insn->imm == BPF_FUNC_redirect_map) { + u64 addr = (unsigned long)prog; + struct bpf_insn r4_ld[] = { + BPF_LD_IMM64(BPF_REG_4, addr), + *insn, + }; + cnt = ARRAY_SIZE(r4_ld); + + new_prog = bpf_patch_insn_data(env, i + delta, r4_ld, cnt); + if (!new_prog) + return -ENOMEM; + + delta += cnt - 1; + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + } patch_call_imm: fn = prog->aux->ops->get_func_proto(insn->imm); /* all functions that have prototype and verifier allowed diff --git a/net/core/filter.c b/net/core/filter.c index 5912c738a7b2..0848df2cd9bf 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1794,6 +1794,7 @@ struct redirect_info { u32 flags; struct bpf_map *map; struct bpf_map *map_to_flush; + const struct bpf_prog *map_owner; }; static DEFINE_PER_CPU(struct redirect_info, redirect_info); @@ -1807,7 +1808,6 @@ BPF_CALL_2(bpf_redirect, u32, ifindex, u64, flags) ri->ifindex = ifindex; ri->flags = flags; - ri->map = NULL; return TC_ACT_REDIRECT; } @@ -2504,6 +2504,7 @@ static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp, struct bpf_prog *xdp_prog) { struct redirect_info *ri = this_cpu_ptr(&redirect_info); + const struct bpf_prog *map_owner = ri->map_owner; struct bpf_map *map = ri->map; u32 index = ri->ifindex; struct net_device *fwd; @@ -2511,6 +2512,15 @@ static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp, ri->ifindex = 0; ri->map = NULL; + ri->map_owner = NULL; + + /* This is really only caused by a deliberately crappy + * BPF program, normally we would never hit that case, + * so no need to inform someone via tracepoints either, + * just bail out. + */ + if (unlikely(map_owner != xdp_prog)) + return -EINVAL; fwd = __dev_map_lookup_elem(map, index); if (!fwd) { @@ -2607,6 +2617,8 @@ BPF_CALL_2(bpf_xdp_redirect, u32, ifindex, u64, flags) ri->ifindex = ifindex; ri->flags = flags; + ri->map = NULL; + ri->map_owner = NULL; return XDP_REDIRECT; } @@ -2619,7 +2631,8 @@ static const struct bpf_func_proto bpf_xdp_redirect_proto = { .arg2_type = ARG_ANYTHING, }; -BPF_CALL_3(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex, u64, flags) +BPF_CALL_4(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex, u64, flags, + const struct bpf_prog *, map_owner) { struct redirect_info *ri = this_cpu_ptr(&redirect_info); @@ -2629,10 +2642,14 @@ BPF_CALL_3(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex, u64, flags ri->ifindex = ifindex; ri->flags = flags; ri->map = map; + ri->map_owner = map_owner; return XDP_REDIRECT; } +/* Note, arg4 is hidden from users and populated by the verifier + * with the right pointer. + */ static const struct bpf_func_proto bpf_xdp_redirect_map_proto = { .func = bpf_xdp_redirect_map, .gpl_only = false, |