On 05/10/2018 08:53 PM, Casey Schaufler wrote: > From: Casey Schaufler <casey(a)schaufler-ca.com&gt; > 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 <casey(a)schaufler-ca.com&gt; > --- > 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).