diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/selinux/hooks.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index a049b7216270..4de09f0227b4 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -254,10 +254,21 @@ static void inode_free_security(struct inode *inode) struct inode_security_struct *isec = inode->i_security; struct superblock_security_struct *sbsec = inode->i_sb->s_security; - spin_lock(&sbsec->isec_lock); - if (!list_empty(&isec->list)) + /* + * As not all inode security structures are in a list, we check for + * empty list outside of the lock to make sure that we won't waste + * time taking a lock doing nothing. + * + * The list_del_init() function can be safely called more than once. + * It should not be possible for this function to be called with + * concurrent list_add(), but for better safety against future changes + * in the code, we use list_empty_careful() here. + */ + if (!list_empty_careful(&isec->list)) { + spin_lock(&sbsec->isec_lock); list_del_init(&isec->list); - spin_unlock(&sbsec->isec_lock); + spin_unlock(&sbsec->isec_lock); + } /* * The inode may still be referenced in a path walk and |