[PATCH] selinux: fix sb_lock/sb_security_lock nesting
From: Stephen Smalley <sds@tycho.nsa.gov>
Fix unsafe nesting of sb_lock inside sb_security_lock in
selinux_complete_init. Detected by the kernel locking validator.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 21dad41..90b4cdc 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4422,6 +4422,7 @@
/* Set up any superblocks initialized prior to the policy load. */
printk(KERN_INFO "SELinux: Setting up existing superblocks.\n");
+ spin_lock(&sb_lock);
spin_lock(&sb_security_lock);
next_sb:
if (!list_empty(&superblock_security_head)) {
@@ -4430,19 +4431,20 @@
struct superblock_security_struct,
list);
struct super_block *sb = sbsec->sb;
- spin_lock(&sb_lock);
sb->s_count++;
- spin_unlock(&sb_lock);
spin_unlock(&sb_security_lock);
+ spin_unlock(&sb_lock);
down_read(&sb->s_umount);
if (sb->s_root)
superblock_doinit(sb, NULL);
drop_super(sb);
+ spin_lock(&sb_lock);
spin_lock(&sb_security_lock);
list_del_init(&sbsec->list);
goto next_sb;
}
spin_unlock(&sb_security_lock);
+ spin_unlock(&sb_lock);
}
/* SELinux requires early initialization in order to label