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 autolearn=ham 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 69A87C32792 for ; Sat, 5 Oct 2019 04:26:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A24120862 for ; Sat, 5 Oct 2019 04:26:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726426AbfJEE0H (ORCPT ); Sat, 5 Oct 2019 00:26:07 -0400 Received: from mail-io1-f69.google.com ([209.85.166.69]:56374 "EHLO mail-io1-f69.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725862AbfJEE0H (ORCPT ); Sat, 5 Oct 2019 00:26:07 -0400 Received: by mail-io1-f69.google.com with SMTP id a22so16590248ioq.23 for ; Fri, 04 Oct 2019 21:26:06 -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:message-id:subject:from:to; bh=JicPHQHtTSbBshE8bs+6VPJwLYumWiA15ciS+bvP4iE=; b=c80FhJPWq8GkP2TO3Q9iNfMAG5scAKuGu+tk3PrNmBsLXChCaXDKeqso7RytekQkFe ctNX/mZ39uvAFlHVKDvSDAb6/BiaIEuDid2mhzDs/zO1NIzOcsygCTT0VJ9iG29X52fL 4G6N7Citm3e/VsF0yqS32BLq5IOjDMi1Ph/9dLuaOTsU4i52gT9rpaIgVTwO4RAx5t4a AqsKTNPKZ4v+2jTrIqGHST/1CpXOVmIyoXy86e1UEStY6B6u+oh1Ps1IhgKxjY1UzRKs bRArxK4zo3aTGjyuH0e1vdycoGneKBV7n0Mb+7kr8F/VY6sUAUHIPL0Ydou9WKoZshoj Fxdg== X-Gm-Message-State: APjAAAWs5eA5SBTDsN/s/erPuMuxwJ3l0UYlZveN7Mcx9L3n8xdczqvV 1EH4ngUKPpGUGZkGf6lFvOuip2vXAPkF3WWRujMGHgsiU2N1 X-Google-Smtp-Source: APXvYqwFL3hynsbxDl5d1CSWTQeQYw1RNZmAEsoxPfIuOumah/1EdLfRbDT+3MzFnyFOUdW6ndKA3mcR4QiLd7xS/5B9ySAX/POb MIME-Version: 1.0 X-Received: by 2002:a92:d282:: with SMTP id p2mr19669488ilp.238.1570249566270; Fri, 04 Oct 2019 21:26:06 -0700 (PDT) Date: Fri, 04 Oct 2019 21:26:06 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000009b403005942237bf@google.com> Subject: KCSAN: data-race in taskstats_exit / taskstats_exit From: syzbot To: bsingharora@gmail.com, elver@google.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com 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: b4bd9343 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=125329db600000 kernel config: https://syzkaller.appspot.com/x/.config?x=c0906aa620713d80 dashboard link: https://syzkaller.appspot.com/bug?extid=c5d03165a1bd1dead0c1 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+c5d03165a1bd1dead0c1@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in taskstats_exit / taskstats_exit write to 0xffff8881157bbe10 of 8 bytes by task 7951 on cpu 0: taskstats_tgid_alloc kernel/taskstats.c:567 [inline] taskstats_exit+0x6b7/0x717 kernel/taskstats.c:596 do_exit+0x2c2/0x18e0 kernel/exit.c:864 do_group_exit+0xb4/0x1c0 kernel/exit.c:983 get_signal+0x2a2/0x1320 kernel/signal.c:2734 do_signal+0x3b/0xc00 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x2d7/0x2f0 arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8881157bbe10 of 8 bytes by task 7949 on cpu 1: taskstats_tgid_alloc kernel/taskstats.c:559 [inline] taskstats_exit+0xb2/0x717 kernel/taskstats.c:596 do_exit+0x2c2/0x18e0 kernel/exit.c:864 do_group_exit+0xb4/0x1c0 kernel/exit.c:983 __do_sys_exit_group kernel/exit.c:994 [inline] __se_sys_exit_group kernel/exit.c:992 [inline] __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:992 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 7949 Comm: syz-executor.3 Not tainted 5.3.0+ #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: 7949 Comm: syz-executor.3 Not tainted 5.3.0+ #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+0x209/0x639 kernel/panic.c:219 end_report kernel/kcsan/report.c:135 [inline] kcsan_report.cold+0x57/0xeb kernel/kcsan/report.c:283 __kcsan_setup_watchpoint+0x342/0x500 kernel/kcsan/core.c:456 __tsan_read8 kernel/kcsan/kcsan.c:31 [inline] __tsan_read8+0x2c/0x30 kernel/kcsan/kcsan.c:31 taskstats_tgid_alloc kernel/taskstats.c:559 [inline] taskstats_exit+0xb2/0x717 kernel/taskstats.c:596 do_exit+0x2c2/0x18e0 kernel/exit.c:864 do_group_exit+0xb4/0x1c0 kernel/exit.c:983 __do_sys_exit_group kernel/exit.c:994 [inline] __se_sys_exit_group kernel/exit.c:992 [inline] __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:992 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x459a59 Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffc4ccf3408 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000001e RCX: 0000000000459a59 RDX: 0000000000413741 RSI: fffffffffffffff7 RDI: 0000000000000000 RBP: 0000000000000000 R08: 000000007f8e4506 R09: 00007ffc4ccf3460 R10: ffffffff81007108 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc4ccf3460 R14: 0000000000000000 R15: 00007ffc4ccf3470 Kernel Offset: disabled Rebooting in 86400 seconds.. --- This bug is generated by a bot. 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