From 5f8d28f6d7d568dbbc8c5bce94894474c07afd4f Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Wed, 10 Jul 2024 14:32:26 -0700 Subject: lsm: infrastructure management of the key security blob Move management of the key->security blob out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. There are no existing modules that require a key_free hook, so the call to it and the definition for it have been removed. Signed-off-by: Casey Schaufler Reviewed-by: John Johansen [PM: subject tweak] Signed-off-by: Paul Moore --- security/security.c | 39 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 37 insertions(+), 2 deletions(-) (limited to 'security/security.c') diff --git a/security/security.c b/security/security.c index 9c3fb2f60e2a..dfb7fea6080c 100644 --- a/security/security.c +++ b/security/security.c @@ -227,6 +227,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed) blob_sizes.lbs_inode = sizeof(struct rcu_head); lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode); lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc); + lsm_set_blob_size(&needed->lbs_key, &blob_sizes.lbs_key); lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg); lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock); lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock); @@ -402,6 +403,9 @@ static void __init ordered_lsm_init(void) init_debug("file blob size = %d\n", blob_sizes.lbs_file); init_debug("inode blob size = %d\n", blob_sizes.lbs_inode); init_debug("ipc blob size = %d\n", blob_sizes.lbs_ipc); +#ifdef CONFIG_KEYS + init_debug("key blob size = %d\n", blob_sizes.lbs_key); +#endif /* CONFIG_KEYS */ init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg); init_debug("sock blob size = %d\n", blob_sizes.lbs_sock); init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock); @@ -718,6 +722,29 @@ static int lsm_ipc_alloc(struct kern_ipc_perm *kip) return 0; } +#ifdef CONFIG_KEYS +/** + * lsm_key_alloc - allocate a composite key blob + * @key: the key that needs a blob + * + * Allocate the key blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_key_alloc(struct key *key) +{ + if (blob_sizes.lbs_key == 0) { + key->security = NULL; + return 0; + } + + key->security = kzalloc(blob_sizes.lbs_key, GFP_KERNEL); + if (key->security == NULL) + return -ENOMEM; + return 0; +} +#endif /* CONFIG_KEYS */ + /** * lsm_msg_msg_alloc - allocate a composite msg_msg blob * @mp: the msg_msg that needs a blob @@ -5316,7 +5343,14 @@ EXPORT_SYMBOL(security_skb_classify_flow); int security_key_alloc(struct key *key, const struct cred *cred, unsigned long flags) { - return call_int_hook(key_alloc, key, cred, flags); + int rc = lsm_key_alloc(key); + + if (unlikely(rc)) + return rc; + rc = call_int_hook(key_alloc, key, cred, flags); + if (unlikely(rc)) + security_key_free(key); + return rc; } /** @@ -5327,7 +5361,8 @@ int security_key_alloc(struct key *key, const struct cred *cred, */ void security_key_free(struct key *key) { - call_void_hook(key_free, key); + kfree(key->security); + key->security = NULL; } /** -- cgit v1.2.3-70-g09d2