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 21749C5DF60 for ; Thu, 7 Nov 2019 18:55:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EFFCA21882 for ; Thu, 7 Nov 2019 18:55:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728448AbfKGSzP (ORCPT ); Thu, 7 Nov 2019 13:55:15 -0500 Received: from mail-il1-f197.google.com ([209.85.166.197]:42117 "EHLO mail-il1-f197.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726811AbfKGSzM (ORCPT ); Thu, 7 Nov 2019 13:55:12 -0500 Received: by mail-il1-f197.google.com with SMTP id n16so3605205ilm.9 for ; Thu, 07 Nov 2019 10:55:10 -0800 (PST) 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=ncLHvCMcrTLEL3uLU3CyiqGHvpiV5fStvg1s9KU5q9Y=; b=iGMOijl/xH8NxgMLhzD1HHr2z5rH/CekZPki62hHAA48O864LltPMXxv0GJ2pXL2Yr jqK20OVlT4m0oTDly3etH0pblyMhZC9kzjme7nrbux3gleT+DXTZYCEyFVkxbdPajOWr 1fUF76sRxylK4wecQfbO/4PAmbS4hrfO5nVteXcrBasUO9i67zaL1AE1fzsagR0OiT3p RIVk7lZCONup0xnjX6/s9J4bO3haDO4MxQeGI83yDqhoFZrArCFL1b6oa3bh/YzqZa7L 8VoAbYr0gsqGHgDNI+LZ9GPBjePxJMsT3QKir+T2QjJ1UHUEUFjQ814M6nXj4nFUjbUC 0uZQ== X-Gm-Message-State: APjAAAXSvblQq/XIF+UjK8HvfvZHa+fhG4vf7gkxGC7auDNlLHftkobF RL9KbiUhHqtjFnOhjnMcepPz+xRNTG7XRfNIZnQ2/OcMcBpd X-Google-Smtp-Source: APXvYqwu+NO9F4IWA1pOKF2v1GmJWS4zEFUZ9BuEmpGqON5v+RXmNcCbkzeCr8UHY4pYUB0TzbbUvHQuLcZkO6FyaEkG9nM10/4S MIME-Version: 1.0 X-Received: by 2002:a92:ce06:: with SMTP id b6mr6266104ilo.14.1573152909795; Thu, 07 Nov 2019 10:55:09 -0800 (PST) Date: Thu, 07 Nov 2019 10:55:09 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000005daaaf0596c634bc@google.com> Subject: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg From: syzbot To: ap420073@gmail.com, davem@davemloft.net, dsahern@gmail.com, elver@google.com, herbert@gondor.apana.org.au, jakub.kicinski@netronome.com, linux-kernel@vger.kernel.org, lirongqing@baidu.com, netdev@vger.kernel.org, penguin-kernel@I-love.SAKURA.ne.jp, ptalbert@redhat.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes 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: 94c00660 x86, kcsan: Enable KCSAN for x86 git tree: https://github.com/google/ktsan.git kcsan console output: https://syzkaller.appspot.com/x/log.txt?x=14426768e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=51a7c7d2972c87e5 dashboard link: https://syzkaller.appspot.com/bug?extid=6dedf50d68e5713a1f65 compiler: gcc (GCC) 9.0.0 20181231 (experimental) 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+6dedf50d68e5713a1f65@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg write to 0xffff8880b588efb2 of 2 bytes by task 19788 on cpu 0: skb_reset_transport_header include/linux/skbuff.h:2463 [inline] netlink_recvmsg+0x196/0x910 net/netlink/af_netlink.c:1974 sock_recvmsg_nosec+0x5c/0x70 net/socket.c:871 ___sys_recvmsg+0x1a0/0x3e0 net/socket.c:2480 do_recvmmsg+0x19a/0x5c0 net/socket.c:2601 __sys_recvmmsg+0x1ef/0x200 net/socket.c:2680 __do_sys_recvmmsg net/socket.c:2703 [inline] __se_sys_recvmmsg net/socket.c:2696 [inline] __x64_sys_recvmmsg+0x89/0xb0 net/socket.c:2696 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 write to 0xffff8880b588efb2 of 2 bytes by task 19789 on cpu 1: skb_reset_transport_header include/linux/skbuff.h:2463 [inline] netlink_recvmsg+0x196/0x910 net/netlink/af_netlink.c:1974 sock_recvmsg_nosec net/socket.c:871 [inline] sock_recvmsg net/socket.c:889 [inline] sock_recvmsg+0x92/0xb0 net/socket.c:885 __sys_recvfrom+0x1ae/0x2d0 net/socket.c:2009 __do_sys_recvfrom net/socket.c:2027 [inline] __se_sys_recvfrom net/socket.c:2023 [inline] __x64_sys_recvfrom+0x89/0xb0 net/socket.c:2023 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 19789 Comm: syz-executor.0 Not tainted 5.4.0-rc6+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 19789 Comm: syz-executor.0 Not tainted 5.4.0-rc6+ #0 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+0xf5/0x159 lib/dump_stack.c:113 panic+0x210/0x640 kernel/panic.c:221 kcsan_report.cold+0xc/0xe kernel/kcsan/report.c:302 kcsan_setup_watchpoint+0x3fe/0x410 kernel/kcsan/core.c:357 check_access kernel/kcsan/core.c:409 [inline] __tsan_unaligned_write2+0x143/0x1f0 kernel/kcsan/core.c:528 skb_reset_transport_header include/linux/skbuff.h:2463 [inline] netlink_recvmsg+0x196/0x910 net/netlink/af_netlink.c:1974 sock_recvmsg_nosec net/socket.c:871 [inline] sock_recvmsg net/socket.c:889 [inline] sock_recvmsg+0x92/0xb0 net/socket.c:885 __sys_recvfrom+0x1ae/0x2d0 net/socket.c:2009 __do_sys_recvfrom net/socket.c:2027 [inline] __se_sys_recvfrom net/socket.c:2023 [inline] __x64_sys_recvfrom+0x89/0xb0 net/socket.c:2023 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45a219 Code: ad b6 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f580a978c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002d RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045a219 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f580a9796d4 R13: 00000000004c7c59 R14: 00000000004ddd80 R15: 00000000ffffffff 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.