Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755704AbdDDS7K (ORCPT ); Tue, 4 Apr 2017 14:59:10 -0400 Received: from mail-lf0-f65.google.com ([209.85.215.65]:34710 "EHLO mail-lf0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753852AbdDDS4t (ORCPT ); Tue, 4 Apr 2017 14:56:49 -0400 From: Dmitry Monakhov To: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, martin.petersen@oracle.com Cc: Dmitry Monakhov Subject: [PATCH 1/9] bio-integrity: Do not allocate integrity context for bio w/o data Date: Tue, 4 Apr 2017 22:56:33 +0400 Message-Id: <1491332201-26926-2-git-send-email-dmonakhov@openvz.org> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1491332201-26926-1-git-send-email-dmonakhov@openvz.org> References: <1491332201-26926-1-git-send-email-dmonakhov@openvz.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1960 Lines: 57 If bio has no data, such as ones from blkdev_issue_flush(), then we have nothing to protect. This patch prevent bugon like follows: kfree_debugcheck: out of range ptr ac1fa1d106742a5ah kernel BUG at mm/slab.c:2773! invalid opcode: 0000 [#1] SMP Modules linked in: bcache CPU: 0 PID: 4428 Comm: xfs_io Tainted: G W 4.11.0-rc4-ext4-00041-g2ef0043-dirty #43 Hardware name: Virtuozzo KVM, BIOS seabios-1.7.5-11.vz7.4 04/01/2014 task: ffff880137786440 task.stack: ffffc90000ba8000 RIP: 0010:kfree_debugcheck+0x25/0x2a RSP: 0018:ffffc90000babde0 EFLAGS: 00010082 RAX: 0000000000000034 RBX: ac1fa1d106742a5a RCX: 0000000000000007 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88013f3ccb40 RBP: ffffc90000babde8 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000fcb76420 R11: 00000000725172ed R12: 0000000000000282 R13: ffffffff8150e766 R14: ffff88013a145e00 R15: 0000000000000001 FS: 00007fb09384bf40(0000) GS:ffff88013f200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd0172f9e40 CR3: 0000000137fa9000 CR4: 00000000000006f0 Call Trace: kfree+0xc8/0x1b3 bio_integrity_free+0xc3/0x16b bio_free+0x25/0x66 bio_put+0x14/0x26 blkdev_issue_flush+0x7a/0x85 blkdev_fsync+0x35/0x42 vfs_fsync_range+0x8e/0x9f vfs_fsync+0x1c/0x1e do_fsync+0x31/0x4a SyS_fsync+0x10/0x14 entry_SYSCALL_64_fastpath+0x1f/0xc2 Reviewed-by: Christoph Hellwig Signed-off-by: Dmitry Monakhov --- block/bio-integrity.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/bio-integrity.c b/block/bio-integrity.c index 5384713..b5009a8 100644 --- a/block/bio-integrity.c +++ b/block/bio-integrity.c @@ -175,6 +175,9 @@ bool bio_integrity_enabled(struct bio *bio) if (bio_op(bio) != REQ_OP_READ && bio_op(bio) != REQ_OP_WRITE) return false; + if (!bio_sectors(bio)) + return false; + /* Already protected? */ if (bio_integrity(bio)) return false; -- 2.9.3