From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.7 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58FD1C282E1 for ; Mon, 22 Apr 2019 16:06:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31BAF20881 for ; Mon, 22 Apr 2019 16:06:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726421AbfDVQGG (ORCPT ); Mon, 22 Apr 2019 12:06:06 -0400 Received: from mail-it1-f198.google.com ([209.85.166.198]:52053 "EHLO mail-it1-f198.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726761AbfDVQGF (ORCPT ); Mon, 22 Apr 2019 12:06:05 -0400 Received: by mail-it1-f198.google.com with SMTP id y127so12928575itb.1 for ; Mon, 22 Apr 2019 09:06:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=7f2B0qDJ0NGKdfmC5nRFEVu9THrNzuuLQq94MmJHVqQ=; b=LXAkZavcMDpAr+StaBhC3jutOwIFDgTSnl8cNqcLrp52e+GmUiGdVsABJGoPNc+lxV JMiix98/2iz0IkjeggNzcgJ4l7jifcYoRQe1/v1UaDIHFRS86HkkCadaJbsLxmog2sb2 NIFbD/aQT1fsW5aTvhELOESM9S+gCBUSo3FUFjwRc6+mYu16DPvJp6tpSJo6G4C974B3 kKkQnU1U8HQnuZPFKCBGd5/A3yn8eoAbdKhIvM+mke5pKKrPd8hWFyVVMHug0pjB0wrv q5DfLFC/nmuGCtIxM70i/M1r3X9sjfNM7qcDUzMRpQfivi3EKp6LOCcnvkQyFWRifTke UhSQ== X-Gm-Message-State: APjAAAWOKtFODAvxKbZ4foX8NIPkH9kQcsEEFMVjX7uGqNXmvUJwVBtY 5LWkWIwLndy02jLMANPdY77Arqyl+nQbUtUEp2OV3uFUQxgf X-Google-Smtp-Source: APXvYqyiIeoejZHRLVRlzClbMGkAsacRLzUQppmw76boahG2dDk+oC18efBUJJNOKiFhJBEwHtznRpbtZ4fOUGfVJRgHUYp5P7ni MIME-Version: 1.0 X-Received: by 2002:a05:6602:2109:: with SMTP id x9mr6515182iox.94.1555949164951; Mon, 22 Apr 2019 09:06:04 -0700 (PDT) Date: Mon, 22 Apr 2019 09:06:04 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000043fe9c058720a5d3@google.com> Subject: WARNING in percpu_ref_kill_and_confirm From: syzbot To: arnd@arndb.de, axboe@kernel.dk, bp@alien8.de, darrick.wong@oracle.com, gregkh@linuxfoundation.org, hpa@zytor.com, linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, luto@kernel.org, mathieu.desnoyers@efficios.com, mingo@redhat.com, mpe@ellerman.id.au, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, x86@kernel.org Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 9e5de623 Merge tag 'nfs-for-5.1-5' of git://git.linux-nfs... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15624257200000 kernel config: https://syzkaller.appspot.com/x/.config?x=856fc6d0fbbeede9 dashboard link: https://syzkaller.appspot.com/bug?extid=10d25e23199614b7721f compiler: gcc (GCC) 9.0.0 20181231 (experimental) userspace arch: i386 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17ff39f3200000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15758647200000 The bug was bisected to: commit 38e7571c07be01f9f19b355a9306a4e3d5cb0f5b Author: Linus Torvalds Date: Fri Mar 8 22:48:40 2019 +0000 Merge tag 'io_uring-2019-03-06' of git://git.kernel.dk/linux-block bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1736bc57200000 final crash: https://syzkaller.appspot.com/x/report.txt?x=14b6bc57200000 console output: https://syzkaller.appspot.com/x/log.txt?x=10b6bc57200000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+10d25e23199614b7721f@syzkaller.appspotmail.com Fixes: 38e7571c07be ("Merge tag 'io_uring-2019-03-06' of git://git.kernel.dk/linux-block") ------------[ cut here ]------------ percpu_ref_kill_and_confirm called more than once on io_ring_ctx_ref_free! WARNING: CPU: 1 PID: 7815 at lib/percpu-refcount.c:335 percpu_ref_kill_and_confirm+0x341/0x3b0 lib/percpu-refcount.c:335 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 7815 Comm: syz-executor269 Not tainted 5.1.0-rc5+ #77 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 panic+0x2cb/0x65c kernel/panic.c:214 __warn.cold+0x20/0x45 kernel/panic.c:571 report_bug+0x263/0x2b0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:179 [inline] fixup_bug arch/x86/kernel/traps.c:174 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973 RIP: 0010:percpu_ref_kill_and_confirm+0x341/0x3b0 lib/percpu-refcount.c:335 Code: 42 e0 2a 06 01 48 89 fa 48 c1 ea 03 80 3c 02 00 75 76 49 8b 54 24 10 48 c7 c6 a0 71 a1 87 48 c7 c7 40 71 a1 87 e8 ad 92 13 fe <0f> 0b 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 RSP: 0018:ffff8880a96cfce0 EFLAGS: 00010086 RAX: 0000000000000000 RBX: 0000607f5142e35b RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815afcf6 RDI: ffffed10152d9f8e RBP: ffff8880a96cfd10 R08: ffff8880a85c40c0 R09: fffffbfff1133639 R10: fffffbfff1133638 R11: ffffffff8899b1c3 R12: ffff88809ee571c0 R13: ffff88809ee571c8 R14: 0000000000000286 R15: 0000000000000000 percpu_ref_kill include/linux/percpu-refcount.h:128 [inline] __io_uring_register+0xa7/0x1fe0 fs/io_uring.c:2937 __do_sys_io_uring_register fs/io_uring.c:2998 [inline] __se_sys_io_uring_register fs/io_uring.c:2980 [inline] __ia32_sys_io_uring_register+0x193/0x1f0 fs/io_uring.c:2980 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x281/0xc98 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f16869 Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f7ef11ec EFLAGS: 00000296 ORIG_RAX: 00000000000001ab RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds.. --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches