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[review,14/19] mnt: Fix the error check in __detach_mounts

Message ID 1428026183-14879-14-git-send-email-ebiederm@xmission.com (mailing list archive)
State New, archived
Headers show

Commit Message

Eric W. Biederman April 3, 2015, 1:56 a.m. UTC
lookup_mountpoint can return either NULL or an error value.
Update the test in __detach_mounts to test for an error value
to avoid pathological cases causing a NULL pointer dereferences.

The callers of __detach_mounts should prevent it from ever being
called on an unlinked dentry but don't take any chances.

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
 fs/namespace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox

Patch

diff --git a/fs/namespace.c b/fs/namespace.c
index 1894d1878dbc..e8f7f8c58c3c 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1516,7 +1516,7 @@  void __detach_mounts(struct dentry *dentry)
 
 	namespace_lock();
 	mp = lookup_mountpoint(dentry);
-	if (!mp)
+	if (IS_ERR_OR_NULL(mp))
 		goto out_unlock;
 
 	lock_mount_hash();