Re: [stable] 3.0.0-rc2-git1 -- BUG: sleeping function called frominvalid context at mm/slub.c:847

From: Greg KH
Date: Wed Jun 08 2011 - 20:08:51 EST


On Wed, Jun 08, 2011 at 03:07:47PM -0700, John Johansen wrote:
> From: John Johansen <john.johansen@xxxxxxxxxxxxx>
> Date: Wed, 8 Jun 2011 15:03:58 -0700
> Subject: [PATCH] AppArmor: Fix sleep in invalid context from task_setrlimit
>
> Affected kernels 2.6.36 - 3.0
>
> AppArmor may do a GFP_KERNEL memory allocation with task_lock(tsk->group_leader);
> held when called from security_task_setrlimit. This will only occur when the
> task's current policy has been replaced, and the task's creds have not been
> updated before entering the LSM security_task_setrlimit() hook.
>
> As reported by Miles Lane
>
> BUG: sleeping function called from invalid context at mm/slub.c:847
> in_atomic(): 1, irqs_disabled(): 0, pid: 1583, name: cupsd
> 2 locks held by cupsd/1583:
> #0: (tasklist_lock){.+.+.+}, at: [<ffffffff8104dafa>] do_prlimit+0x61/0x189
> #1: (&(&p->alloc_lock)->rlock){+.+.+.}, at: [<ffffffff8104db2d>]
> do_prlimit+0x94/0x189
> Pid: 1583, comm: cupsd Not tainted 3.0.0-rc2-git1 #7
> Call Trace:
> [<ffffffff8102ebf2>] __might_sleep+0x10d/0x112
> [<ffffffff810e6f46>] slab_pre_alloc_hook.isra.49+0x2d/0x33
> [<ffffffff810e7bc4>] kmem_cache_alloc+0x22/0x132
> [<ffffffff8105b6e6>] prepare_creds+0x35/0xe4
> [<ffffffff811c0675>] aa_replace_current_profile+0x35/0xb2
> [<ffffffff811c4d2d>] aa_current_profile+0x45/0x4c
> [<ffffffff811c4d4d>] apparmor_task_setrlimit+0x19/0x3a
> [<ffffffff811beaa5>] security_task_setrlimit+0x11/0x13
> [<ffffffff8104db6b>] do_prlimit+0xd2/0x189
> [<ffffffff8104dea9>] sys_setrlimit+0x3b/0x48
> [<ffffffff814062bb>] system_call_fastpath+0x16/0x1b
>
> Signed-off-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
> ---
> security/apparmor/lsm.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read Documentation/stable_kernel_rules.txt
for how to do this properly.

</formletter>
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