On 5/14/2018 8:04 AM, Stephen Smalley wrote: > On 05/10/2018 08:53 PM, Casey Schaufler wrote: >> From: Casey Schaufler <ca...@schaufler-ca.com> >> Date: Thu, 10 May 2018 14:23:27 -0700 >> Subject: [PATCH 10/23] LSM: Infrastructure management of the inode security >> blob >> >> Move management of the inode->i_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. >> >> Signed-off-by: Casey Schaufler <ca...@schaufler-ca.com> >> --- >> include/linux/lsm_hooks.h | 3 ++ >> security/security.c | 85 >> +++++++++++++++++++++++++++++++++++++-- >> security/selinux/hooks.c | 32 +-------------- >> security/selinux/include/objsec.h | 5 +-- >> security/smack/smack_lsm.c | 70 +++++--------------------------- >> 5 files changed, 99 insertions(+), 96 deletions(-) >> <SNIP> >> diff --git a/security/security.c b/security/security.c >> index b414186ad45f..02df9b608b7e 100644 >> --- a/security/security.c >> +++ b/security/security.c >> @@ -41,6 +41,7 @@ struct security_hook_heads security_hook_heads >> __lsm_ro_after_init; >> static ATOMIC_NOTIFIER_HEAD(lsm_notifier_chain); >> >> static struct kmem_cache *lsm_file_cache; >> +static struct kmem_cache *lsm_inode_cache; >> >> char *lsm_names; >> static struct lsm_blob_sizes blob_sizes; >> @@ -98,6 +99,10 @@ int __init security_init(void) >> lsm_file_cache = kmem_cache_create("lsm_file_cache", >> blob_sizes.lbs_file, 0, >> SLAB_PANIC, NULL); >> + if (blob_sizes.lbs_inode) >> + lsm_inode_cache = kmem_cache_create("lsm_inode_cache", >> + blob_sizes.lbs_inode, 0, >> + SLAB_PANIC, NULL); >> /* >> * The second call to a module specific init function >> * adds hooks to the hook lists and does any other early >> @@ -108,8 +113,9 @@ int __init security_init(void) >> #ifdef CONFIG_SECURITY_LSM_DEBUG >> pr_info("LSM: cred blob size = %d\n", blob_sizes.lbs_cred); >> pr_info("LSM: file blob size = %d\n", blob_sizes.lbs_file); >> + pr_info("LSM: inode blob size = %d\n", blob_sizes.lbs_inode); >> pr_info("LSM: task blob size = %d\n", blob_sizes.lbs_task); >> -#endif >> +#endif /* CONFIG_SECURITY_LSM_DEBUG */ >> >> return 0; >> } >> @@ -285,6 +291,13 @@ void __init security_add_blobs(struct lsm_blob_sizes >> *needed) >> lsm_set_size(&needed->lbs_cred, &blob_sizes.lbs_cred); >> lsm_set_size(&needed->lbs_file, &blob_sizes.lbs_file); >> lsm_set_size(&needed->lbs_task, &blob_sizes.lbs_task); >> + /* >> + * The inode blob gets an rcu_head in addition to >> + * what the modules might need. >> + */ >> + if (needed->lbs_inode && blob_sizes.lbs_inode == 0) >> + blob_sizes.lbs_inode = sizeof(struct rcu_head); >> + lsm_set_size(&needed->lbs_inode, &blob_sizes.lbs_inode); >> } >> >> /** >> @@ -348,6 +361,46 @@ void lsm_early_task(struct task_struct *task) >> panic("%s: Early task alloc failed.\n", __func__); >> } >> >> +/** >> + * lsm_inode_alloc - allocate a composite inode blob >> + * @inode: the inode that needs a blob >> + * >> + * Allocate the inode blob for all the modules >> + * >> + * Returns 0, or -ENOMEM if memory can't be allocated. >> + */ >> +int lsm_inode_alloc(struct inode *inode) >> +{ >> + if (!lsm_inode_cache) { >> + inode->i_security = NULL; >> + return 0; >> + } >> + >> + inode->i_security = kmem_cache_zalloc(lsm_inode_cache, GFP_KERNEL); > Should be GFP_NOFS (and was that way in SELinux and Smack).
Yes, you're correct. I'll make the change.