diff options
| author | Blaise Boscaccy <bboscaccy@linux.microsoft.com> | 2025-07-22 14:21:34 -0700 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2025-08-11 17:56:09 -0400 |
| commit | 5816bf4273edb32716a88c796e0b04f0e12962eb (patch) | |
| tree | 539cd5d2886c3651e23124c5ec913cf053bdb843 /security/security.c | |
| parent | e5bc887413e513a2cb658370dd09fa9e1702fb3b (diff) | |
| download | linux-5816bf4273edb32716a88c796e0b04f0e12962eb.tar.gz | |
lsm,selinux: Add LSM blob support for BPF objects
This patch introduces LSM blob support for BPF maps, programs, and
tokens to enable LSM stacking and multiplexing of LSM modules that
govern BPF objects. Additionally, the existing BPF hooks used by
SELinux have been updated to utilize the new blob infrastructure,
removing the assumption of exclusive ownership of the security
pointer.
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
[PM: dropped local variable init, style fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'security/security.c')
| -rw-r--r-- | security/security.c | 86 |
1 files changed, 83 insertions, 3 deletions
diff --git a/security/security.c b/security/security.c index a88ebfca322420..ca126b02d2feed 100644 --- a/security/security.c +++ b/security/security.c @@ -283,6 +283,9 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed) lsm_set_blob_size(&needed->lbs_xattr_count, &blob_sizes.lbs_xattr_count); lsm_set_blob_size(&needed->lbs_bdev, &blob_sizes.lbs_bdev); + lsm_set_blob_size(&needed->lbs_bpf_map, &blob_sizes.lbs_bpf_map); + lsm_set_blob_size(&needed->lbs_bpf_prog, &blob_sizes.lbs_bpf_prog); + lsm_set_blob_size(&needed->lbs_bpf_token, &blob_sizes.lbs_bpf_token); } /* Prepare LSM for initialization. */ @@ -480,6 +483,9 @@ static void __init ordered_lsm_init(void) init_debug("tun device blob size = %d\n", blob_sizes.lbs_tun_dev); init_debug("xattr slots = %d\n", blob_sizes.lbs_xattr_count); init_debug("bdev blob size = %d\n", blob_sizes.lbs_bdev); + init_debug("bpf map blob size = %d\n", blob_sizes.lbs_bpf_map); + init_debug("bpf prog blob size = %d\n", blob_sizes.lbs_bpf_prog); + init_debug("bpf token blob size = %d\n", blob_sizes.lbs_bpf_token); /* * Create any kmem_caches needed for blobs @@ -827,6 +833,47 @@ static int lsm_bdev_alloc(struct block_device *bdev) GFP_KERNEL); } +#ifdef CONFIG_BPF_SYSCALL +/** + * lsm_bpf_map_alloc - allocate a composite bpf_map blob + * @map: the bpf_map that needs a blob + * + * Allocate the bpf_map blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_bpf_map_alloc(struct bpf_map *map) +{ + return lsm_blob_alloc(&map->security, blob_sizes.lbs_bpf_map, GFP_KERNEL); +} + +/** + * lsm_bpf_prog_alloc - allocate a composite bpf_prog blob + * @prog: the bpf_prog that needs a blob + * + * Allocate the bpf_prog blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_bpf_prog_alloc(struct bpf_prog *prog) +{ + return lsm_blob_alloc(&prog->aux->security, blob_sizes.lbs_bpf_prog, GFP_KERNEL); +} + +/** + * lsm_bpf_token_alloc - allocate a composite bpf_token blob + * @token: the bpf_token that needs a blob + * + * Allocate the bpf_token blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_bpf_token_alloc(struct bpf_token *token) +{ + return lsm_blob_alloc(&token->security, blob_sizes.lbs_bpf_token, GFP_KERNEL); +} +#endif /* CONFIG_BPF_SYSCALL */ + /** * lsm_early_task - during initialization allocate a composite task blob * @task: the task that needs a blob @@ -5706,7 +5753,16 @@ int security_bpf_prog(struct bpf_prog *prog) int security_bpf_map_create(struct bpf_map *map, union bpf_attr *attr, struct bpf_token *token, bool kernel) { - return call_int_hook(bpf_map_create, map, attr, token, kernel); + int rc; + + rc = lsm_bpf_map_alloc(map); + if (unlikely(rc)) + return rc; + + rc = call_int_hook(bpf_map_create, map, attr, token, kernel); + if (unlikely(rc)) + security_bpf_map_free(map); + return rc; } /** @@ -5725,7 +5781,16 @@ int security_bpf_map_create(struct bpf_map *map, union bpf_attr *attr, int security_bpf_prog_load(struct bpf_prog *prog, union bpf_attr *attr, struct bpf_token *token, bool kernel) { - return call_int_hook(bpf_prog_load, prog, attr, token, kernel); + int rc; + + rc = lsm_bpf_prog_alloc(prog); + if (unlikely(rc)) + return rc; + + rc = call_int_hook(bpf_prog_load, prog, attr, token, kernel); + if (unlikely(rc)) + security_bpf_prog_free(prog); + return rc; } /** @@ -5742,7 +5807,16 @@ int security_bpf_prog_load(struct bpf_prog *prog, union bpf_attr *attr, int security_bpf_token_create(struct bpf_token *token, union bpf_attr *attr, const struct path *path) { - return call_int_hook(bpf_token_create, token, attr, path); + int rc; + + rc = lsm_bpf_token_alloc(token); + if (unlikely(rc)) + return rc; + + rc = call_int_hook(bpf_token_create, token, attr, path); + if (unlikely(rc)) + security_bpf_token_free(token); + return rc; } /** @@ -5786,6 +5860,8 @@ int security_bpf_token_capable(const struct bpf_token *token, int cap) void security_bpf_map_free(struct bpf_map *map) { call_void_hook(bpf_map_free, map); + kfree(map->security); + map->security = NULL; } /** @@ -5797,6 +5873,8 @@ void security_bpf_map_free(struct bpf_map *map) void security_bpf_prog_free(struct bpf_prog *prog) { call_void_hook(bpf_prog_free, prog); + kfree(prog->aux->security); + prog->aux->security = NULL; } /** @@ -5808,6 +5886,8 @@ void security_bpf_prog_free(struct bpf_prog *prog) void security_bpf_token_free(struct bpf_token *token) { call_void_hook(bpf_token_free, token); + kfree(token->security); + token->security = NULL; } #endif /* CONFIG_BPF_SYSCALL */ |