From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> [ Upstream commit f53e57975151f54ad8caa1b0ac8a78091cd5700a ] 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@xxxxxxxxxxxxxxx Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx> --- fs/namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/namespace.c b/fs/namespace.c index 8b60287..a19d05c 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1490,7 +1490,7 @@ 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(); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html