Re: current->mm == NULL in security_vm_enough_memory().

From: James Morris
Date: Wed Mar 25 2009 - 21:41:39 EST


On Thu, 26 Mar 2009, Tetsuo Handa wrote:

> [ 28.765817] ------------[ cut here ]------------
> [ 28.768916] WARNING: at security/security.c:217 security_vm_enough_memory+0xa0/0xb0()
> [ 28.772484] Hardware name: VMware Virtual Platform
> [ 28.774099] Modules linked in: pcnet32 crc32
> [ 28.776920] Pid: 3286, comm: khelper Not tainted 2.6.29-next-20090324-dirty #3
> [ 28.780317] Call Trace:
> [ 28.781323] [<c0159200>] ? have_callable_console+0x30/0x50
> [ 28.784171] [<c0158497>] warn_slowpath+0x97/0xf0
> [ 28.785739] [<c0190f7c>] ? validate_chain+0x3fc/0x540
> [ 28.788402] [<c0190f7c>] ? validate_chain+0x3fc/0x540
> [ 28.790103] [<c0192dfc>] ? __lock_acquire+0x29c/0x8a0
> [ 28.792809] [<c0194859>] ? __lock_acquired+0x109/0x1c0
> [ 28.794539] [<c0338ea0>] security_vm_enough_memory+0xa0/0xb0
> [ 28.797391] [<c0202117>] acct_stack_growth+0xd7/0x160
> [ 28.798842] [<c02022b9>] expand_downwards+0x119/0x150
> [ 28.801709] [<c020230d>] expand_stack+0xd/0x10
> [ 28.804171] [<c02023bd>] find_extend_vma+0xad/0x110
> [ 28.805806] [<c01f9c04>] __get_user_pages+0x94/0x610
> [ 28.808557] [<c01fa1fb>] get_user_pages+0x7b/0x90
> [ 28.810483] [<c022c028>] get_arg_page+0x48/0x100
> [ 28.812972] [<c022c58c>] copy_strings+0x16c/0x2a0
> [ 28.814552] [<c022ea52>] do_execve+0x6b2/0x7e0
> [ 28.817138] [<c02320eb>] ? getname+0x6b/0xa0
> [ 28.818622] [<c010237e>] sys_execve+0x5e/0xb0
> [ 28.821006] [<c0103d19>] syscall_call+0x7/0xb
> [ 28.822469] [<c010ae94>] ? kernel_execve+0x24/0x30
> [ 28.825161] [<c01729af>] ? ____call_usermodehelper+0xff/0x170
> [ 28.828052] [<c01728b0>] ? ____call_usermodehelper+0x0/0x170
> [ 28.829944] [<c0104707>] ? kernel_thread_helper+0x7/0x10
> [ 28.832802] ---[ end trace 2e6964f14bb57083 ]---
>
> May I ignore this warning?

khelper is a kernel thread, so it should not have an ->mm, but I wonder
why this hasn't shown up before. Odd...


- James
--
James Morris
<jmorris@xxxxxxxxx>
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