Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace fix from Eric Biederman:
"Benjamin Coddington noticed an unkillable busy loop in the kernel that
anyone who is sufficiently motivated can trigger. This bug did not
exist in earlier kernels making this bug a regression.
I have tested the change personally and confirmed that the bug exists
and that the fix works. This fix has been picked up by linux-next and
hopefully the automated testing bots and no problems have been
reported from those sources.
Ordinarily I would let something like this sit a little longer but I
am going to be away at Linux Plumbers the rest of this week and I am
afraid if I don't send the pull request now this fix will get lost"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
mnt: fix __detach_mounts infinite loop
diff --git a/fs/namespace.c b/fs/namespace.c
index 74f6429..a7f9126 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -695,9 +695,6 @@ static struct mountpoint *lookup_mountpoint(struct dentry *dentry)
hlist_for_each_entry(mp, chain, m_hash) {
if (mp->m_dentry == dentry) {
- /* might be worth a WARN_ON() */
- if (d_unlinked(dentry))
- return ERR_PTR(-ENOENT);
mp->m_count++;
return mp;
}
@@ -711,6 +708,9 @@ static struct mountpoint *get_mountpoint(struct dentry *dentry)
int ret;
if (d_mountpoint(dentry)) {
+ /* might be worth a WARN_ON() */
+ if (d_unlinked(dentry))
+ return ERR_PTR(-ENOENT);
mountpoint:
read_seqlock_excl(&mount_lock);
mp = lookup_mountpoint(dentry);