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

From: Tetsuo Handa
Date: Wed Mar 25 2009 - 21:31:40 EST


Hello.

2.6.28 and later have a "current->mm != NULL" checking
added by commit 731572d39fcd3498702eda4600db4c43d51e0b26 .

int security_vm_enough_memory(long pages)
{
WARN_ON(current->mm == NULL);
return security_ops->vm_enough_memory(current->mm, pages);
}

I encountered this warning on Debian Sarge.
Config is at http://I-love.SAKURA.ne.jp/tmp/config-2.6.29-next-20090324 .

Mounting local filesystems...
[ 18.746829] kjournald starting. Commit interval 5 seconds
[ 18.754102] EXT3 FS on sdb1, internal journal
[ 18.756928] EXT3-fs: mounted filesystem with ordered data mode.
/dev/sdb1 on /usr/src/all type ext3 (rw,noatime,nodiratime)
Cleaning /tmp /var/run /var/lock.
Detecting hardware: agpgart pcnet32 piix BusLogic ide_scsi
Skipping unavailable/built-in agpgart module.
pcnet32 disabled in configuration.
Skipping unavailable/built-in piix module.
Skipping unavailable/built-in BusLogic module.
Skipping unavailable/built-in ide_scsi module.
Running 0dns-down to make sure resolv.conf is ok...done.
Setting up networking...done.
Starting hotplug subsystem:
pci
ignoring pci display device 00:0f.0
[ 28.728908] pcnet32.c:v1.35 21.Apr.2008 tsbogend@xxxxxxxxxxxxxxxx
[ 28.735902] pcnet32: PCnet/PCI II 79C970A at 0x2000, 00:0c:29:9e:eb:32 assigned IRQ 18.
[ 28.754197] eth0: registered as PCnet/PCI II 79C970A
[ 28.758543] pcnet32: 1 cards_found.
[ 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?

Regards.
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