Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753842AbdDEGce (ORCPT ); Wed, 5 Apr 2017 02:32:34 -0400 Received: from mx2.suse.de ([195.135.220.15]:43622 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752938AbdDEGcd (ORCPT ); Wed, 5 Apr 2017 02:32:33 -0400 Subject: Re: [PATCH 1/9] bio-integrity: Do not allocate integrity context for bio w/o data To: Dmitry Monakhov , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, martin.petersen@oracle.com References: <1491332201-26926-1-git-send-email-dmonakhov@openvz.org> <1491332201-26926-2-git-send-email-dmonakhov@openvz.org> From: Hannes Reinecke Message-ID: <062accdf-a6c4-7cdf-db87-262c8410465e@suse.de> Date: Wed, 5 Apr 2017 08:32:30 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <1491332201-26926-2-git-send-email-dmonakhov@openvz.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2414 Lines: 68 On 04/04/2017 08:56 PM, Dmitry Monakhov wrote: > 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; > Reviewed-by: Hannes Reinecke Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N?rnberg GF: F. Imend?rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG N?rnberg)