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=-0.7 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 61597C43219 for ; Thu, 2 May 2019 02:38:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 36FE920645 for ; Thu, 2 May 2019 02:38:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726341AbfEBCiG (ORCPT ); Wed, 1 May 2019 22:38:06 -0400 Received: from mail-io1-f69.google.com ([209.85.166.69]:40357 "EHLO mail-io1-f69.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726186AbfEBCiG (ORCPT ); Wed, 1 May 2019 22:38:06 -0400 Received: by mail-io1-f69.google.com with SMTP id y10so717641ioj.7 for ; Wed, 01 May 2019 19:38:06 -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:in-reply-to:message-id:subject :from:to; bh=xtXw2lupwkVjqX6efEcOaASU6ebh70LIWoergDKWJSw=; b=cuj5vhwsqR5Wbh1hKBPa1Ip08tMGq3RCGr4fmOIlNRiDt5FkxJK5yQsC6P65ehY0BH HEYekat6Rpz5KTHT+HpmumJnsQh5B1A9ezQLs77dcBqIz5eBhaKihwAvMG+knzCGzqpK EONqQn4B2Bg3wahEYoKJMg4qiU580rNQoAOgWnsZZHwrL7x8yAsUPlE+UlCWASmEWjl9 C/b33LpKxbQPLXqChzVj/0cA4SFQDptrvBJ9/Kg8UTvR/ytKRNd3ib0+s/ZrwA0zHTiM 28RsfZrKy4Dq4QYVkYt8Zp89ScLxAwewkdgwAg6523KeRK5IguxRHtEkB6UQsWGaXfs+ 3WKA== X-Gm-Message-State: APjAAAXr7a46I3DUuBPk7xKQGlYdhc89WF75PS8G8+IqttRelODsq/Bj U2sV/c00EADDBW3cRMCmAbHzZX/ZNlXHEwlpN8fHSFbOV1X3 X-Google-Smtp-Source: APXvYqwQqZI+dOYyfu+U0r6fq/+CcfSqb4y1MWdnmVWFreVqywSXoJDTxuiE6SA1+xZcYWY9y+SAgmmGSNCZZOO6qEp0cHUzU/nJ MIME-Version: 1.0 X-Received: by 2002:a5d:83d7:: with SMTP id u23mr897843ior.56.1556764685538; Wed, 01 May 2019 19:38:05 -0700 (PDT) Date: Wed, 01 May 2019 19:38:05 -0700 In-Reply-To: <000000000000eb6a8e057ab79f82@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000149c440587de8693@google.com> Subject: Re: WARNING: refcount bug in p9_req_put From: syzbot To: asmadeus@codewreck.org, davem@davemloft.net, ericvh@gmail.com, linux-kernel@vger.kernel.org, lucho@ionkov.net, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com, v9fs-developer@lists.sourceforge.net Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org syzbot has found a reproducer for the following crash on: HEAD commit: 459e3a21 gcc-9: properly declare the {pv,hv}clock_page sto.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=136c9284a00000 kernel config: https://syzkaller.appspot.com/x/.config?x=ef1b87b455c397cf dashboard link: https://syzkaller.appspot.com/bug?extid=edec7868af5997928fe9 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1642ee48a00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+edec7868af5997928fe9@syzkaller.appspotmail.com WARNING: CPU: 1 PID: 7959 at lib/refcount.c:190 refcount_sub_and_test_checked lib/refcount.c:190 [inline] WARNING: CPU: 1 PID: 7959 at lib/refcount.c:190 refcount_sub_and_test_checked+0x1d0/0x200 lib/refcount.c:180 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 7959 Comm: syz-executor.1 Not tainted 5.1.0-rc7+ #96 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:refcount_sub_and_test_checked lib/refcount.c:190 [inline] RIP: 0010:refcount_sub_and_test_checked+0x1d0/0x200 lib/refcount.c:180 Code: 1d c8 30 2a 06 31 ff 89 de e8 0c 32 40 fe 84 db 75 94 e8 c3 30 40 fe 48 c7 c7 60 79 a1 87 c6 05 a8 30 2a 06 01 e8 ae de 12 fe <0f> 0b e9 75 ff ff ff e8 a4 30 40 fe e9 6e ff ff ff 48 89 df e8 37 RSP: 0018:ffff888089ce7860 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff815afcb6 RDI: ffffed101139cefe RBP: ffff888089ce78f8 R08: ffff8880a4c584c0 R09: ffffed1015d25011 R10: ffffed1015d25010 R11: ffff8880ae928087 R12: 00000000ffffffff R13: 0000000000000001 R14: ffff888089ce78d0 R15: 0000000000000000 refcount_dec_and_test_checked+0x1b/0x20 lib/refcount.c:220 kref_put include/linux/kref.h:66 [inline] p9_req_put+0x20/0x60 net/9p/client.c:401 p9_conn_destroy net/9p/trans_fd.c:880 [inline] p9_fd_close+0x2ee/0x570 net/9p/trans_fd.c:913 p9_client_create+0x998/0x1400 net/9p/client.c:1083 v9fs_session_init+0x1e7/0x1960 fs/9p/v9fs.c:421 v9fs_mount+0x7d/0x920 fs/9p/vfs_super.c:135 legacy_get_tree+0xf2/0x200 fs/fs_context.c:584 vfs_get_tree+0x123/0x450 fs/super.c:1481 do_new_mount fs/namespace.c:2622 [inline] do_mount+0x1436/0x2c40 fs/namespace.c:2942 ksys_mount+0xdb/0x150 fs/namespace.c:3151 __do_sys_mount fs/namespace.c:3165 [inline] __se_sys_mount fs/namespace.c:3162 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3162 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2e68c68c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f2e68c68c90 RCX: 0000000000458da9 RDX: 0000000020000100 RSI: 00000000200000c0 RDI: 0000000000000000 RBP: 000000000073bf00 R08: 00000000200013c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2e68c696d4 R13: 00000000004c4da7 R14: 00000000004d8a20 R15: 0000000000000005 Kernel Offset: disabled Rebooting in 86400 seconds..