diff options
| -rw-r--r-- | include/linux/bpf.h | 6 | ||||
| -rw-r--r-- | include/linux/lsm_hooks.h | 55 | ||||
| -rw-r--r-- | include/linux/security.h | 45 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 34 | ||||
| -rw-r--r-- | security/security.c | 48 |
5 files changed, 185 insertions, 3 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 13b2ae12f902..7e8326737cd3 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -46,6 +46,9 @@ struct bpf_map { const struct bpf_map_ops *ops; struct work_struct work; atomic_t usercnt; +#ifdef CONFIG_SECURITY + void *security; +#endif }; struct bpf_map_type_list { @@ -179,6 +182,9 @@ struct bpf_prog_aux { struct bpf_map **used_maps; struct bpf_prog *prog; struct user_struct *user; +#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 8a9bffb2dac4..479ddf6811f5 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1297,7 +1297,40 @@ * @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. - * This is the main security structure. + * + * 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 { @@ -1616,6 +1649,17 @@ 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 { @@ -1829,6 +1873,15 @@ 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 */ }; /* diff --git a/include/linux/security.h b/include/linux/security.h index 96eacf534163..11a06d0c9dad 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -29,6 +29,7 @@ #include <linux/string.h> #include <linux/mm.h> #include <linux/bio.h> +#include <linux/bpf.h> struct linux_binprm; struct cred; @@ -1623,6 +1624,50 @@ 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 c050dfbb4858..53dbfb4020f2 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -121,6 +121,7 @@ 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); } @@ -209,6 +210,12 @@ 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); } @@ -256,10 +263,14 @@ 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_new_fd(map, f_flags); if (err < 0) /* failed to allocate fd */ @@ -269,6 +280,8 @@ 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; @@ -716,6 +729,7 @@ 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); } @@ -742,6 +756,12 @@ 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); } @@ -843,10 +863,14 @@ 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; @@ -889,6 +913,8 @@ 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; @@ -1035,6 +1061,10 @@ 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 6cced62a81b6..65748c3b37ef 100644 --- a/security/security.c +++ b/security/security.c @@ -11,6 +11,7 @@ * (at your option) any later version. */ +#include <linux/bpf.h> #include <linux/capability.h> #include <linux/dcache.h> #include <linux/module.h> @@ -1554,6 +1555,37 @@ int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule, } #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 */ + struct security_hook_heads security_hook_heads = { .binder_set_context_mgr = LIST_HEAD_INIT(security_hook_heads.binder_set_context_mgr), @@ -1900,4 +1932,20 @@ struct security_hook_heads security_hook_heads = { .audit_rule_free = LIST_HEAD_INIT(security_hook_heads.audit_rule_free), #endif /* CONFIG_AUDIT */ +#ifdef CONFIG_BPF_SYSCALL + .bpf = + LIST_HEAD_INIT(security_hook_heads.bpf), + .bpf_map = + LIST_HEAD_INIT(security_hook_heads.bpf_map), + .bpf_prog = + LIST_HEAD_INIT(security_hook_heads.bpf_prog), + .bpf_map_alloc_security = + LIST_HEAD_INIT(security_hook_heads.bpf_map_alloc_security), + .bpf_map_free_security = + LIST_HEAD_INIT(security_hook_heads.bpf_map_free_security), + .bpf_prog_alloc_security = + LIST_HEAD_INIT(security_hook_heads.bpf_prog_alloc_security), + .bpf_prog_free_security = + LIST_HEAD_INIT(security_hook_heads.bpf_prog_free_security), +#endif /* CONFIG_BPF_SYSCALL */ }; 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