Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754036Ab2KFIBD (ORCPT ); Tue, 6 Nov 2012 03:01:03 -0500 Received: from mail-vc0-f174.google.com ([209.85.220.174]:32828 "EHLO mail-vc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753805Ab2KFIBA (ORCPT ); Tue, 6 Nov 2012 03:01:00 -0500 MIME-Version: 1.0 In-Reply-To: <50984676.1080307@redhat.com> References: <1352155633-8648-1-git-send-email-walken@google.com> <1352155633-8648-2-git-send-email-walken@google.com> <50984676.1080307@redhat.com> Date: Tue, 6 Nov 2012 00:00:59 -0800 Message-ID: Subject: Re: [PATCH 01/16] mm: add anon_vma_lock to validate_mm() From: Michel Lespinasse To: Sasha Levin , Bob Liu Cc: Rik van Riel , Andrew Morton , Hugh Dickins , linux-kernel@vger.kernel.org, linux-mm@kvack.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3791 Lines: 84 Adding Sasha and Bob, which I forgot to CC in the original message. On Mon, Nov 5, 2012 at 3:06 PM, Rik van Riel wrote: > On 11/05/2012 05:46 PM, Michel Lespinasse wrote: >> >> Iterate vma->anon_vma_chain without anon_vma_lock may cause NULL ptr deref >> in >> anon_vma_interval_tree_verify(), because the node in the chain might have >> been >> removed. >> >> [ 1523.657950] BUG: unable to handle kernel paging request at >> fffffffffffffff0 >> [ 1523.660022] IP: [] >> anon_vma_interval_tree_verify+0xc/0xa0 >> [ 1523.660022] PGD 4e28067 PUD 4e29067 PMD 0 >> [ 1523.675725] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC >> [ 1523.750066] CPU 0 >> [ 1523.750066] Pid: 9050, comm: trinity-child64 Tainted: G W >> 3.7.0-rc2-next-20121025-sasha-00001-g673f98e-dirty #77 >> [ 1523.750066] RIP: 0010:[] [] >> anon_vma_interval_tree_verify+0xc/0xa0 >> [ 1523.750066] RSP: 0018:ffff880045f81d48 EFLAGS: 00010296 >> [ 1523.750066] RAX: 0000000000000000 RBX: fffffffffffffff0 RCX: >> 0000000000000000 >> [ 1523.750066] RDX: 0000000000000000 RSI: 0000000000000001 RDI: >> fffffffffffffff0 >> [ 1523.750066] RBP: ffff880045f81d58 R08: 0000000000000000 R09: >> 0000000000000f14 >> [ 1523.750066] R10: 0000000000000f12 R11: 0000000000000000 R12: >> ffff8800096c8d70 >> [ 1523.750066] R13: ffff8800096c8d00 R14: 0000000000000000 R15: >> ffff8800095b45e0 >> [ 1523.750066] FS: 00007f7a923f3700(0000) GS:ffff880013600000(0000) >> knlGS:0000000000000000 >> [ 1523.750066] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> [ 1523.750066] CR2: fffffffffffffff0 CR3: 000000000969d000 CR4: >> 00000000000406f0 >> [ 1523.750066] DR0: 0000000000000000 DR1: 0000000000000000 DR2: >> 0000000000000000 >> [ 1523.750066] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: >> 0000000000000400 >> [ 1523.750066] Process trinity-child64 (pid: 9050, threadinfo >> ffff880045f80000, task ffff880048eb0000) >> [ 1523.750066] Stack: >> [ 1523.750066] ffff88000d7533f0 fffffffffffffff0 ffff880045f81da8 >> ffffffff812361d8 >> [ 1523.750066] ffff880045f81d98 ffff880048ee9000 ffff8800095b4580 >> ffff8800095b4580 >> [ 1523.750066] ffff88001d1cdb00 ffff8800095b45f0 ffff880022a4d630 >> ffff8800095b45e0 >> [ 1523.750066] Call Trace: >> [ 1523.750066] [] validate_mm+0x58/0x1e0 >> [ 1523.750066] [] vma_adjust+0x635/0x6b0 >> [ 1523.750066] [] __split_vma.isra.22+0x161/0x220 >> [ 1523.750066] [] split_vma+0x24/0x30 >> [ 1523.750066] [] sys_madvise+0x5da/0x7b0 >> [ 1523.750066] [] ? rcu_eqs_exit+0x9c/0xb0 >> [ 1523.750066] [] ? trace_hardirqs_on+0xd/0x10 >> [ 1523.750066] [] tracesys+0xe1/0xe6 >> [ 1523.750066] Code: 4c 09 ff 48 39 ce 77 9e f3 c3 0f 1f 44 00 00 31 c0 c3 >> 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 53 >> 48 89 fb 48 83 ec 08 <48> 8b 17 48 8b 8a 90 00 00 00 48 39 4f 40 74 34 80 >> 3d f7 1f 5c >> [ 1523.750066] RIP [] >> anon_vma_interval_tree_verify+0xc/0xa0 >> [ 1523.750066] RSP >> [ 1523.750066] CR2: fffffffffffffff0 >> [ 1523.750066] ---[ end trace e35e5fa49072faf9 ]--- >> >> Reported-by: Sasha Levin >> Figured-out-by: Bob Liu >> Signed-off-by: Michel Lespinasse > > Reviewed-by: Rik van Riel -- Michel "Walken" Lespinasse A program is never fully debugged until the last user dies. -- 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/