Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762139AbXHKSNf (ORCPT ); Sat, 11 Aug 2007 14:13:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754348AbXHKSN2 (ORCPT ); Sat, 11 Aug 2007 14:13:28 -0400 Received: from ug-out-1314.google.com ([66.249.92.174]:20259 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752101AbXHKSN1 (ORCPT ); Sat, 11 Aug 2007 14:13:27 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:date:from:to:cc:subject:message-id:references:mime-version:content-type:content-disposition:in-reply-to:user-agent; b=Qg0fobj0lGGPoU8DX1AXNhIDM55WXzfyLRpf6XvI9jF3D10NvDX4uzR9pc5b8R0T1nXVKZyNHS33hLKLzDTw5o55cWtjjLe++nghQwR+o73yqjWO+A86b3T4YyQwgyy+vyV00rjw29Pd+O1nwRaL+vXhblhRHWn5d8M5L/xzvWM= Date: Sat, 11 Aug 2007 22:13:10 +0400 From: Cyrill Gorcunov To: Balbir Singh Cc: Andrew Morton , linux-kernel , WU Fengguang Subject: Re: [BUGFIX] NULL pointer dereference in __vm_enough_memory() Message-ID: <20070811181310.GB7232@cvg> References: <386838491.27058@ustc.edu.cn> <661de9470708110730r1267bdfdp1e76546e11b64f78@mail.gmail.com> <20070811100015.2417788e.akpm@linux-foundation.org> <46BDF965.3050402@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46BDF965.3050402@linux.vnet.ibm.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4882 Lines: 104 [Balbir Singh - Sat, Aug 11, 2007 at 11:31:09PM +0530] | Andrew Morton wrote: | > On Sat, 11 Aug 2007 20:00:12 +0530 "Balbir Singh" wrote: | > | >> On 8/11/07, Fengguang Wu wrote: | > | > hm, both people who replied to this removed Fengguang from cc. Disagreement | > between headers and MUAs, perhaps? | > | | Oops... Not sure how that happened. I'll check my sent mail. | | >>> Andrew, | >>> | >>> I'm not sure if this patch is the right fix for the bug. But it do | >>> stops the oops message. The bug also happens in 2.6.23-rc1-mm2/2.6.23-rc2-mm2. | >>> I'm running debian/sid. The .config is attached. | >>> | >>> | >>> Unable to handle kernel NULL pointer dereference at 0000000000000138 RIP | >>> [] __vm_enough_memory+0x76/0x120 | >>> PGD 7cd84067 PUD 7d9c3067 PMD 0 | >>> Oops: 0000 [2] SMP | >>> CPU 1 | >>> Modules linked in: eeprom lm85 hwmon_vid i2c_core tun fuse kvm snd_hda_intel snd_pcm_oss snd_mixer_oss snd_pcm snd_timer sg snd soundcore sr_mod cdrom snd_page_alloc pcspkr evdev button raid0 usbhid sd_mod uhci_hcd ehci_hcd ata_piix ahci ohci1394 ieee1394 thermal processor fan | >>> Pid: 4305, comm: khelper Tainted: G D 2.6.23-rc2 #9 | >>> RIP: 0010:[] [] __vm_enough_memory+0x76/0x120 | >>> RSP: 0000:ffff81007a3d1d30 EFLAGS: 00010206 | >>> RAX: 0000000000000000 RBX: 0000000000000001 RCX: 000000000003e142 | >>> RDX: 00000000000004f4 RSI: 0000000000000001 RDI: 0000000000000001 | >>> RBP: ffff81007a3d1d40 R08: ffff81007a3d1d78 R09: 0000000000000000 | >>> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 | >>> R13: 0000000000000000 R14: ffff81007d0c0188 R15: ffff81007d577b18 | >>> FS: 0000000000000000(0000) GS:ffff81007efa11d0(0000) knlGS:0000000000000000 | >>> CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b | >>> CR2: 0000000000000138 CR3: 000000003799b000 CR4: 00000000000006e0 | >>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 | >>> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 | >>> Process khelper (pid: 4305, threadinfo ffff81007a3d0000, task ffff81007a30acc0) | >>> Stack: 0000000000000001 ffff81007d577b18 ffff81007a3d1d60 ffffffff811297ff | >>> 0000000000000001 ffff810037c84bb8 ffff81007a3d1da0 ffffffff81092532 | >>> ffff81007d0c0188 0000000000000000 ffff81007d577b20 0000000000000000 | >>> Call Trace: | >>> [] cap_vm_enough_memory+0x2f/0x40 | >>> [] insert_vm_struct+0xa2/0xb0 | >>> [] bprm_mm_init+0x11e/0x1b0 | >>> [] do_execve+0x81/0x220 | >>> [] __call_usermodehelper+0x0/0x90 | >>> [] sys_execve+0x46/0xb0 | >>> [] __call_usermodehelper+0x0/0x90 | >>> [] kernel_execve+0x64/0xd0 | >>> [] __call_usermodehelper+0x0/0x90 | >>> [] ____call_usermodehelper+0x174/0x190 | >>> [] child_rip+0xa/0x12 | >>> [] schedule_tail+0x78/0x100 | >>> [] restore_args+0x0/0x30 | >>> [] ____call_usermodehelper+0x0/0x190 | >>> [] child_rip+0x0/0x12 | >>> | >>> | >>> Code: 48 8b 80 38 01 00 00 48 c1 e8 05 48 29 c1 48 39 ca 0f 8c 89 | >>> RIP [] __vm_enough_memory+0x76/0x120 | >>> RSP | >>> CR2: 0000000000000138 | >>> | >>> Signed-off-by: Fengguang Wu | >>> --- | >>> mm/mmap.c | 3 ++- | >>> 1 file changed, 2 insertions(+), 1 deletion(-) | >>> | >>> --- linux-2.6.23-rc2-mm2.orig/mm/mmap.c | >>> +++ linux-2.6.23-rc2-mm2/mm/mmap.c | >>> @@ -166,7 +166,8 @@ int __vm_enough_memory(long pages, int c | >>> | >>> /* Don't let a single process grow too big: | >>> leave 3% of the size of this process for other processes */ | >>> - allowed -= current->mm->total_vm / 32; | >>> + if (current->mm) | >>> + allowed -= current->mm->total_vm / 32; | >>> | >>> /* | >>> * cast `allowed' as a signed long because vm_committed_space | >>> | >>> | >> Shouldn't we just not stop vm accounting for kernel threads? | >> | > | > Could be. It'd help heaps if we knew which patch in -mm caused | > this, but from a quick peek it seems to me that mainline should be | > vulnerable as well. | | Thats a valid point. It would be interesting to see what the overcommit | setting was, when the panic occurred. May I suggest - could it be commit b6a2fea39318e43fee84fa7b0b90d68bed92d2ba Not sure but take a look please Cyrill - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/