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-rw-r--r--include/linux/bpf.h6
-rw-r--r--include/linux/lsm_hooks.h54
-rw-r--r--include/linux/security.h45
-rw-r--r--kernel/bpf/syscall.c34
-rw-r--r--security/security.c32
5 files changed, 169 insertions, 2 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 3e5508f2fa87..84c192da3e0b 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -57,6 +57,9 @@ struct bpf_map {
atomic_t usercnt;
struct bpf_map *inner_map_meta;
char name[BPF_OBJ_NAME_LEN];
+#ifdef CONFIG_SECURITY
+ void *security;
+#endif
};
/* function argument constraints */
@@ -193,6 +196,9 @@ struct bpf_prog_aux {
struct user_struct *user;
u64 load_time; /* ns since boottime */
char name[BPF_OBJ_NAME_LEN];
+#ifdef CONFIG_SECURITY
+ void *security;
+#endif
union {
struct work_struct work;
struct rcu_head rcu;
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index c9258124e417..7161d8e7ee79 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1351,6 +1351,40 @@
* @inode we wish to get the security context of.
* @ctx is a pointer in which to place the allocated security context.
* @ctxlen points to the place to put the length of @ctx.
+ *
+ * Security hooks for using the eBPF maps and programs functionalities through
+ * eBPF syscalls.
+ *
+ * @bpf:
+ * Do a initial check for all bpf syscalls after the attribute is copied
+ * into the kernel. The actual security module can implement their own
+ * rules to check the specific cmd they need.
+ *
+ * @bpf_map:
+ * Do a check when the kernel generate and return a file descriptor for
+ * eBPF maps.
+ *
+ * @map: bpf map that we want to access
+ * @mask: the access flags
+ *
+ * @bpf_prog:
+ * Do a check when the kernel generate and return a file descriptor for
+ * eBPF programs.
+ *
+ * @prog: bpf prog that userspace want to use.
+ *
+ * @bpf_map_alloc_security:
+ * Initialize the security field inside bpf map.
+ *
+ * @bpf_map_free_security:
+ * Clean up the security information stored inside bpf map.
+ *
+ * @bpf_prog_alloc_security:
+ * Initialize the security field inside bpf program.
+ *
+ * @bpf_prog_free_security:
+ * Clean up the security information stored inside bpf prog.
+ *
*/
union security_list_options {
int (*binder_set_context_mgr)(struct task_struct *mgr);
@@ -1682,6 +1716,17 @@ union security_list_options {
struct audit_context *actx);
void (*audit_rule_free)(void *lsmrule);
#endif /* CONFIG_AUDIT */
+
+#ifdef CONFIG_BPF_SYSCALL
+ int (*bpf)(int cmd, union bpf_attr *attr,
+ unsigned int size);
+ int (*bpf_map)(struct bpf_map *map, fmode_t fmode);
+ int (*bpf_prog)(struct bpf_prog *prog);
+ int (*bpf_map_alloc_security)(struct bpf_map *map);
+ void (*bpf_map_free_security)(struct bpf_map *map);
+ int (*bpf_prog_alloc_security)(struct bpf_prog_aux *aux);
+ void (*bpf_prog_free_security)(struct bpf_prog_aux *aux);
+#endif /* CONFIG_BPF_SYSCALL */
};
struct security_hook_heads {
@@ -1901,6 +1946,15 @@ struct security_hook_heads {
struct list_head audit_rule_match;
struct list_head audit_rule_free;
#endif /* CONFIG_AUDIT */
+#ifdef CONFIG_BPF_SYSCALL
+ struct list_head bpf;
+ struct list_head bpf_map;
+ struct list_head bpf_prog;
+ struct list_head bpf_map_alloc_security;
+ struct list_head bpf_map_free_security;
+ struct list_head bpf_prog_alloc_security;
+ struct list_head bpf_prog_free_security;
+#endif /* CONFIG_BPF_SYSCALL */
} __randomize_layout;
/*
diff --git a/include/linux/security.h b/include/linux/security.h
index ce6265960d6c..18800b0911e5 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -31,6 +31,7 @@
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/fs.h>
+#include <linux/bpf.h>
struct linux_binprm;
struct cred;
@@ -1730,6 +1731,50 @@ static inline void securityfs_remove(struct dentry *dentry)
#endif
+#ifdef CONFIG_BPF_SYSCALL
+#ifdef CONFIG_SECURITY
+extern int security_bpf(int cmd, union bpf_attr *attr, unsigned int size);
+extern int security_bpf_map(struct bpf_map *map, fmode_t fmode);
+extern int security_bpf_prog(struct bpf_prog *prog);
+extern int security_bpf_map_alloc(struct bpf_map *map);
+extern void security_bpf_map_free(struct bpf_map *map);
+extern int security_bpf_prog_alloc(struct bpf_prog_aux *aux);
+extern void security_bpf_prog_free(struct bpf_prog_aux *aux);
+#else
+static inline int security_bpf(int cmd, union bpf_attr *attr,
+ unsigned int size)
+{
+ return 0;
+}
+
+static inline int security_bpf_map(struct bpf_map *map, fmode_t fmode)
+{
+ return 0;
+}
+
+static inline int security_bpf_prog(struct bpf_prog *prog)
+{
+ return 0;
+}
+
+static inline int security_bpf_map_alloc(struct bpf_map *map)
+{
+ return 0;
+}
+
+static inline void security_bpf_map_free(struct bpf_map *map)
+{ }
+
+static inline int security_bpf_prog_alloc(struct bpf_prog_aux *aux)
+{
+ return 0;
+}
+
+static inline void security_bpf_prog_free(struct bpf_prog_aux *aux)
+{ }
+#endif /* CONFIG_SECURITY */
+#endif /* CONFIG_BPF_SYSCALL */
+
#ifdef CONFIG_SECURITY
static inline char *alloc_secdata(void)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 676a06e6b322..5cb56d06b48d 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -212,6 +212,7 @@ static void bpf_map_free_deferred(struct work_struct *work)
struct bpf_map *map = container_of(work, struct bpf_map, work);
bpf_map_uncharge_memlock(map);
+ security_bpf_map_free(map);
/* implementation dependent freeing */
map->ops->map_free(map);
}
@@ -325,6 +326,12 @@ static const struct file_operations bpf_map_fops = {
int bpf_map_new_fd(struct bpf_map *map, int flags)
{
+ int ret;
+
+ ret = security_bpf_map(map, OPEN_FMODE(flags));
+ if (ret < 0)
+ return ret;
+
return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
flags | O_CLOEXEC);
}
@@ -405,10 +412,14 @@ static int map_create(union bpf_attr *attr)
atomic_set(&map->refcnt, 1);
atomic_set(&map->usercnt, 1);
- err = bpf_map_charge_memlock(map);
+ err = security_bpf_map_alloc(map);
if (err)
goto free_map_nouncharge;
+ err = bpf_map_charge_memlock(map);
+ if (err)
+ goto free_map_sec;
+
err = bpf_map_alloc_id(map);
if (err)
goto free_map;
@@ -430,6 +441,8 @@ static int map_create(union bpf_attr *attr)
free_map:
bpf_map_uncharge_memlock(map);
+free_map_sec:
+ security_bpf_map_free(map);
free_map_nouncharge:
map->ops->map_free(map);
return err;
@@ -914,6 +927,7 @@ static void __bpf_prog_put_rcu(struct rcu_head *rcu)
free_used_maps(aux);
bpf_prog_uncharge_memlock(aux->prog);
+ security_bpf_prog_free(aux);
bpf_prog_free(aux->prog);
}
@@ -972,6 +986,12 @@ static const struct file_operations bpf_prog_fops = {
int bpf_prog_new_fd(struct bpf_prog *prog)
{
+ int ret;
+
+ ret = security_bpf_prog(prog);
+ if (ret < 0)
+ return ret;
+
return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
O_RDWR | O_CLOEXEC);
}
@@ -1111,10 +1131,14 @@ static int bpf_prog_load(union bpf_attr *attr)
if (!prog)
return -ENOMEM;
- err = bpf_prog_charge_memlock(prog);
+ err = security_bpf_prog_alloc(prog->aux);
if (err)
goto free_prog_nouncharge;
+ err = bpf_prog_charge_memlock(prog);
+ if (err)
+ goto free_prog_sec;
+
prog->len = attr->insn_cnt;
err = -EFAULT;
@@ -1172,6 +1196,8 @@ free_used_maps:
free_used_maps(prog->aux);
free_prog:
bpf_prog_uncharge_memlock(prog);
+free_prog_sec:
+ security_bpf_prog_free(prog->aux);
free_prog_nouncharge:
bpf_prog_free(prog);
return err;
@@ -1640,6 +1666,10 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz
if (copy_from_user(&attr, uattr, size) != 0)
return -EFAULT;
+ err = security_bpf(cmd, &attr, size);
+ if (err < 0)
+ return err;
+
switch (cmd) {
case BPF_MAP_CREATE:
err = map_create(&attr);
diff --git a/security/security.c b/security/security.c
index 4bf0f571b4ef..1cd8526cb0b7 100644
--- a/security/security.c
+++ b/security/security.c
@@ -12,6 +12,7 @@
* (at your option) any later version.
*/
+#include <linux/bpf.h>
#include <linux/capability.h>
#include <linux/dcache.h>
#include <linux/module.h>
@@ -1703,3 +1704,34 @@ int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule,
actx);
}
#endif /* CONFIG_AUDIT */
+
+#ifdef CONFIG_BPF_SYSCALL
+int security_bpf(int cmd, union bpf_attr *attr, unsigned int size)
+{
+ return call_int_hook(bpf, 0, cmd, attr, size);
+}
+int security_bpf_map(struct bpf_map *map, fmode_t fmode)
+{
+ return call_int_hook(bpf_map, 0, map, fmode);
+}
+int security_bpf_prog(struct bpf_prog *prog)
+{
+ return call_int_hook(bpf_prog, 0, prog);
+}
+int security_bpf_map_alloc(struct bpf_map *map)
+{
+ return call_int_hook(bpf_map_alloc_security, 0, map);
+}
+int security_bpf_prog_alloc(struct bpf_prog_aux *aux)
+{
+ return call_int_hook(bpf_prog_alloc_security, 0, aux);
+}
+void security_bpf_map_free(struct bpf_map *map)
+{
+ call_void_hook(bpf_map_free_security, map);
+}
+void security_bpf_prog_free(struct bpf_prog_aux *aux)
+{
+ call_void_hook(bpf_prog_free_security, aux);
+}
+#endif /* CONFIG_BPF_SYSCALL */