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| author | Serge E. Hallyn <serue@us.ibm.com> | 2009-02-13 14:04:21 +0000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-02-13 08:07:40 -0800 |
| commit | fb5ae64fdde29236e1a15e0366946df7060f41f2 (patch) | |
| tree | 86be58998529fa84282ec1b98040d707e4b61686 | |
| parent | 37bed90094fdb1eea6e4afec6a200d4e60143e55 (diff) | |
| download | linux-fb5ae64fdde29236e1a15e0366946df7060f41f2.tar.gz linux-fb5ae64fdde29236e1a15e0366946df7060f41f2.tar.bz2 linux-fb5ae64fdde29236e1a15e0366946df7060f41f2.zip | |
User namespaces: Only put the userns when we unhash the uid
uids in namespaces other than init don't get a sysfs entry.
For those in the init namespace, while we're waiting to remove
the sysfs entry for the uid the uid is still hashed, and
alloc_uid() may re-grab that uid without getting a new
reference to the user_ns, which we've already put in free_user
before scheduling remove_user_sysfs_dir().
Reported-and-tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/user.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/user.c b/kernel/user.c index 477b6660f447..3551ac742395 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -72,6 +72,7 @@ static void uid_hash_insert(struct user_struct *up, struct hlist_head *hashent) static void uid_hash_remove(struct user_struct *up) { hlist_del_init(&up->uidhash_node); + put_user_ns(up->user_ns); } static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent) @@ -334,7 +335,6 @@ static void free_user(struct user_struct *up, unsigned long flags) atomic_inc(&up->__count); spin_unlock_irqrestore(&uidhash_lock, flags); - put_user_ns(up->user_ns); INIT_WORK(&up->work, remove_user_sysfs_dir); schedule_work(&up->work); } @@ -357,7 +357,6 @@ static void free_user(struct user_struct *up, unsigned long flags) sched_destroy_user(up); key_put(up->uid_keyring); key_put(up->session_keyring); - put_user_ns(up->user_ns); kmem_cache_free(uid_cachep, up); } |