Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754997Ab2KEWwv (ORCPT ); Mon, 5 Nov 2012 17:52:51 -0500 Received: from mail-pb0-f46.google.com ([209.85.160.46]:64529 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751716Ab2KEWrd (ORCPT ); Mon, 5 Nov 2012 17:47:33 -0500 From: Michel Lespinasse To: Andrew Morton , Rik van Riel , Hugh Dickins , linux-kernel@vger.kernel.org, Russell King , Ralf Baechle , Paul Mundt , "David S. Miller" , Chris Metcalf , x86@kernel.org, William Irwin Cc: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-mips@linux-mips.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org Subject: [PATCH 01/16] mm: add anon_vma_lock to validate_mm() Date: Mon, 5 Nov 2012 14:46:58 -0800 Message-Id: <1352155633-8648-2-git-send-email-walken@google.com> X-Mailer: git-send-email 1.7.7.3 In-Reply-To: <1352155633-8648-1-git-send-email-walken@google.com> References: <1352155633-8648-1-git-send-email-walken@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3794 Lines: 73 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 --- mm/mmap.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 2d942353d681..9a796c41e7d9 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -334,8 +334,10 @@ void validate_mm(struct mm_struct *mm) struct vm_area_struct *vma = mm->mmap; while (vma) { struct anon_vma_chain *avc; + vma_lock_anon_vma(vma); list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) anon_vma_interval_tree_verify(avc); + vma_unlock_anon_vma(vma); vma = vma->vm_next; i++; } -- 1.7.7.3 -- 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/