From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752772AbdK1War (ORCPT ); Tue, 28 Nov 2017 17:30:47 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:51764 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751732AbdK1Wap (ORCPT ); Tue, 28 Nov 2017 17:30:45 -0500 Date: Tue, 28 Nov 2017 14:30:41 -0800 From: "Paul E. McKenney" To: Andrew Morton Cc: syzbot , cl@linux.com, iamjoonsoo.kim@lge.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, penberg@kernel.org, rientjes@google.com, syzkaller-bugs@googlegroups.com, Herbert Xu Subject: Re: WARNING: suspicious RCU usage (3) Reply-To: paulmck@linux.vnet.ibm.com References: <94eb2c03c9bcc3b127055f11171d@google.com> <20171128133026.cf03471c99d7a0c827c5a21c@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171128133026.cf03471c99d7a0c827c5a21c@linux-foundation.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17112822-0036-0000-0000-000002931CDE X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008121; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000242; SDB=6.00952612; UDB=6.00481254; IPR=6.00732694; BA=6.00005719; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00018236; XFM=3.00000015; UTC=2017-11-28 22:30:44 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17112822-0037-0000-0000-00004283DA55 Message-Id: <20171128223041.GZ3624@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-11-28_12:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1711280299 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 28, 2017 at 01:30:26PM -0800, Andrew Morton wrote: > On Tue, 28 Nov 2017 12:45:01 -0800 syzbot wrote: > > > Hello, > > > > syzkaller hit the following crash on > > b0a84f19a5161418d4360cd57603e94ed489915e > > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master > > compiler: gcc (GCC) 7.1.1 20170620 > > .config is attached > > Raw console output is attached. > > > > Unfortunately, I don't have any reproducer for this bug yet. > > > > WARNING: suspicious RCU usage > > There's a bunch of other info which lockdep_rcu_suspicious() should > have printed out, but this trace doesn't have any of it. I wonder why. Yes, there should be more info printed, no idea why it would go missing. Thanx, Paul > > 4.14.0-next-20171127+ #53 Not tainted > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000074 > > IP: virt_to_cache mm/slab.c:400 [inline] > > IP: kfree+0xb2/0x250 mm/slab.c:3803 > > PGD 1cd9be067 P4D 1cd9be067 PUD 1c646d067 PMD 0 > > Oops: 0000 [#1] SMP KASAN > > Dumping ftrace buffer: > > (ftrace buffer empty) > > Modules linked in: > > CPU: 1 PID: 17319 Comm: syz-executor7 Not tainted 4.14.0-next-20171127+ #53 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > task: ffff8801c5442040 task.stack: ffff8801c7ed8000 > > RIP: 0010:virt_to_cache mm/slab.c:400 [inline] > > RIP: 0010:kfree+0xb2/0x250 mm/slab.c:3803 > > RSP: 0018:ffff8801c7edf780 EFLAGS: 00010046 > > RAX: 0000000000000000 RBX: ffff8801c7edf948 RCX: ffffffffffffffff > > RDX: ffffea00071fb7c0 RSI: 0000000000000000 RDI: ffff8801c7edf948 > > RBP: ffff8801c7edf7a0 R08: ffffed003b02866c R09: 0000000000000000 > > R10: 0000000000000001 R11: ffffed003b02866b R12: 0000000000000286 > > R13: 0000000000000000 R14: ffff8801c7edf948 R15: ffff8801c7edf8b0 > > FS: 00007ff14d179700(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 0000000000000074 CR3: 00000001c6768000 CR4: 00000000001426e0 > > Call Trace: > > blkcipher_walk_done+0x72b/0xde0 crypto/blkcipher.c:139 > > encrypt+0x50a/0xaf0 crypto/salsa20_generic.c:208 > > skcipher_crypt_blkcipher crypto/skcipher.c:622 [inline] > > skcipher_encrypt_blkcipher+0x213/0x310 crypto/skcipher.c:631 > > crypto_skcipher_encrypt include/crypto/skcipher.h:445 [inline] > > _skcipher_recvmsg crypto/algif_skcipher.c:144 [inline] > > skcipher_recvmsg+0x9e8/0xf20 crypto/algif_skcipher.c:165 > > sock_recvmsg_nosec net/socket.c:805 [inline] > > sock_recvmsg+0xc9/0x110 net/socket.c:812 > > ___sys_recvmsg+0x29b/0x630 net/socket.c:2207 > > __sys_recvmsg+0xe2/0x210 net/socket.c:2252 > > SYSC_recvmsg net/socket.c:2264 [inline] > > SyS_recvmsg+0x2d/0x50 net/socket.c:2259 > > entry_SYSCALL_64_fastpath+0x1f/0x96 > > It looks like blkcipher_walk_done() passed a bad address to kfree(). > > > RIP: 0033:0x4529d9 > > RSP: 002b:00007ff14d178c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002f > > RAX: ffffffffffffffda RBX: 0000000000758190 RCX: 00000000004529d9 > > RDX: 0000000000010000 RSI: 0000000020d63fc8 RDI: 0000000000000018 > > RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f2728 > > R13: 00000000ffffffff R14: 00007ff14d1796d4 R15: 0000000000000000 > > Code: c2 48 b8 00 00 00 00 00 ea ff ff 48 89 df 48 c1 ea 0c 48 c1 e2 06 48 > > 01 c2 48 8b 42 20 48 8d 48 ff a8 01 48 0f 45 d1 4c 8b 6a 30 <49> 63 75 74 > > e8 b5 5c af ff 48 89 de 4c 89 ef 4c 8b 75 08 e8 76 > > RIP: virt_to_cache mm/slab.c:400 [inline] RSP: ffff8801c7edf780 > > RIP: kfree+0xb2/0x250 mm/slab.c:3803 RSP: ffff8801c7edf780 > > CR2: 0000000000000074 > > ---[ end trace e3c719a9c9d01886 ]--- > > > > > > --- > > This bug is generated by a dumb bot. It may contain errors. > > See https://urldefense.proofpoint.com/v2/url?u=https-3A__goo.gl_tpsmEJ&d=DwICAg&c=jf_iaSHvJObTbx-siA1ZOg&r=q4hkQkeaNH3IlTsPvEwkaUALMqf7y6jCMwT5b6lVQbQ&m=aTCoRUwymtfv220QJqsca2w9mocNKMrzqpgtUF-s558&s=2sG5vQqYSKlZIxmT377N3IAs1G31yBEQVetU4JSSt34&e= for details. > > Direct all questions to syzkaller@googlegroups.com. > > Please credit me with: Reported-by: syzbot > > > > syzbot will keep track of this bug report. > > Once a fix for this bug is committed, please reply to this email with: > > #syz fix: exact-commit-title > > To mark this as a duplicate of another syzbot report, please reply with: > > #syz dup: exact-subject-of-another-report > > If it's a one-off invalid bug report, please reply with: > > #syz invalid > > Note: if the crash happens again, it will cause creation of a new bug > > report. > > Note: all commands must start from beginning of the line in the email body. >