2007-11-21 10:50:02

by Pavel Emelyanov

Subject: [PATCH 1/2] Don't forget to unlock uids_mutex on error paths

The commit

commit 5cb350baf580017da38199625b7365b1763d7180
Author: Dhaval Giani <[email protected]>
Date: Mon Oct 15 17:00:14 2007 +0200

sched: group scheduling, sysfs tunables

introduced the uids_mutex and the helpers to lock/unlock it.
Unfortunately, the error paths of alloc_uid() were not patched
to unlock it.

Signed-off-by: Pavel Emelyanov <[email protected]>

---

diff --git a/kernel/user.c b/kernel/user.c
index 56327ee..3549c4b 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -343,8 +343,11 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid)
struct user_struct *new;

new = kmem_cache_alloc(uid_cachep, GFP_KERNEL);
- if (!new)
+ if (!new) {
+ uids_mutex_unlock();
return NULL;
+ }
+
new->uid = uid;
atomic_set(&new->__count, 1);
atomic_set(&new->processes, 0);
@@ -361,6 +364,7 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid)

if (alloc_uid_keyring(new, current) < 0) {
kmem_cache_free(uid_cachep, new);
+ uids_mutex_unlock();
return NULL;
}

@@ -368,6 +372,7 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid)
key_put(new->uid_keyring);
key_put(new->session_keyring);
kmem_cache_free(uid_cachep, new);
+ uids_mutex_unlock();
return NULL;
}

--
1.5.3.4

2007-11-23 13:13:50

by Dhaval Giani

Subject: Re: [PATCH 1/2] Don't forget to unlock uids_mutex on error paths

On Wed, Nov 21, 2007 at 01:49:33PM +0300, Pavel Emelyanov wrote:
> The commit
>
> commit 5cb350baf580017da38199625b7365b1763d7180
> Author: Dhaval Giani <[email protected]>
> Date: Mon Oct 15 17:00:14 2007 +0200
>
> sched: group scheduling, sysfs tunables
>
> introduced the uids_mutex and the helpers to lock/unlock it.
> Unfortunately, the error paths of alloc_uid() were not patched
> to unlock it.
>

Thanks for catching it. Looks good to me. Ingo, could you please pick
these up?

> Signed-off-by: Pavel Emelyanov <[email protected]>
Acked-by: Dhaval Giani <[email protected]>

--
regards,
Dhaval

2007-11-23 13:53:00

by Ingo Molnar

Subject: Re: [PATCH 1/2] Don't forget to unlock uids_mutex on error paths

* Dhaval Giani <[email protected]> wrote:

> On Wed, Nov 21, 2007 at 01:49:33PM +0300, Pavel Emelyanov wrote:
> > The commit
> >
> > commit 5cb350baf580017da38199625b7365b1763d7180
> > Author: Dhaval Giani <[email protected]>
> > Date: Mon Oct 15 17:00:14 2007 +0200
> >
> > sched: group scheduling, sysfs tunables
> >
> > introduced the uids_mutex and the helpers to lock/unlock it.
> > Unfortunately, the error paths of alloc_uid() were not patched
> > to unlock it.

oops!

> Thanks for catching it. Looks good to me. Ingo, could you please pick
> these up?

yep - added.

Ingo