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=-5.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 C52B0C2BA19 for ; Sat, 18 Apr 2020 06:44:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ADBCF21D91 for ; Sat, 18 Apr 2020 06:44:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726024AbgDRGoV (ORCPT ); Sat, 18 Apr 2020 02:44:21 -0400 Received: from mail-il1-f197.google.com ([209.85.166.197]:47217 "EHLO mail-il1-f197.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725873AbgDRGoQ (ORCPT ); Sat, 18 Apr 2020 02:44:16 -0400 Received: by mail-il1-f197.google.com with SMTP id a15so4719837ild.14 for ; Fri, 17 Apr 2020 23:44:15 -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=pXmS78UP3PIHf/SRcQHxFXu6pvUOOha8DWE8p79NAfc=; b=ViZkYPrWhjgqxQGFJv2A5J/YqqMvuTl9/tY6BG21Uo6BaTEpRCv3MxVDD+XjzcfJ+i SJeA9DjSvy7KUxVSR7y6oEPVayFYob7oQr19KecKm9wpIQTpE2yNBLwHfCYonn4ye/TR ZIi+hlr/K8e7BwgcDDRFTZJHFCx56EMiONAinglw3Ww9fUNkKzH4GmND4CA83VvVaunO C5ER0dnDCMaSpW/G+jqHG2IWjb9uGr6KmqXImj4KiBrp5ZSVrSLD6n6/VCA42Z0mhiGX lNX3AGQMOUV/PI5EqsWKcz/n3uRYLIxt0IqWRZFix1bPD98kSU2CSjVtkM8LhLmEKMNW eqWw== X-Gm-Message-State: AGi0PuY3ftEtaAeQLgXdWTUBB0+yCGg6STMSlWDE8O8VziWKkHSChyZE koCVpFL6gCOnKjGwgIuooZEv9s2r+CE17YNBYOflBNuG4eKu X-Google-Smtp-Source: APiQypLwcu3iOTuryi0ondhPJrW7F+zsa1E+M/lJpkpwzLcRN3No1r+6BnQvVrMCLeiRcr/Lbm77C2pukHrig8tX9tmVPQhe2ipS MIME-Version: 1.0 X-Received: by 2002:a92:39dd:: with SMTP id h90mr6713306ilf.80.1587192254928; Fri, 17 Apr 2020 23:44:14 -0700 (PDT) Date: Fri, 17 Apr 2020 23:44:14 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000008b9e0705a38afe52@google.com> Subject: WARNING: refcount bug in do_enable_set From: syzbot To: davem@davemloft.net, johan.hedberg@gmail.com, kuba@kernel.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, marcel@holtmann.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 8f3d9f35 Linux 5.7-rc1 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1182b24fe00000 kernel config: https://syzkaller.appspot.com/x/.config?x=11f10cc27c63cade dashboard link: https://syzkaller.appspot.com/bug?extid=2e9900a1e1b3c9c96a77 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+2e9900a1e1b3c9c96a77@syzkaller.appspotmail.com ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 10817 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 10817 Comm: kworker/0:7 Not tainted 5.7.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events do_enable_set Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1e9/0x30e lib/dump_stack.c:118 panic+0x264/0x7a0 kernel/panic.c:221 __warn+0x209/0x210 kernel/panic.c:582 report_bug+0x1ac/0x2d0 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:175 [inline] do_error_trap+0xca/0x1c0 arch/x86/kernel/traps.c:267 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027 RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 Code: c7 9a a9 f2 88 31 c0 e8 a3 fb ac fd 0f 0b eb 85 e8 5a e7 da fd c6 05 10 48 cf 05 01 48 c7 c7 c6 a9 f2 88 31 c0 e8 85 fb ac fd <0f> 0b e9 64 ff ff ff e8 39 e7 da fd c6 05 f0 47 cf 05 01 48 c7 c7 RSP: 0000:ffffc900016d7c48 EFLAGS: 00010246 RAX: 8e9964d9ee901300 RBX: 0000000000000003 RCX: ffff888089a0e5c0 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: ffffffff815cbca9 R09: ffffed1015d06660 R10: ffffed1015d06660 R11: 0000000000000000 R12: ffffffff895f43c8 R13: dffffc0000000000 R14: ffff88809365b018 R15: ffff8880ae83b400 do_enable_set+0x63a/0x8d0 net/bluetooth/6lowpan.c:1075 process_one_work+0x76e/0xfd0 kernel/workqueue.c:2268 worker_thread+0xa7f/0x1450 kernel/workqueue.c:2414 kthread+0x353/0x380 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 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.