From: Dmitry Vyukov <dvyukov@google.com>
To: syzbot <syzbot+c5d03165a1bd1dead0c1@syzkaller.appspotmail.com>,
Christian Brauner <christian@brauner.io>
Cc: bsingharora@gmail.com, Marco Elver <elver@google.com>,
LKML <linux-kernel@vger.kernel.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Subject: Re: KCSAN: data-race in taskstats_exit / taskstats_exit
Date: Sat, 5 Oct 2019 06:29:39 +0200 [thread overview]
Message-ID: <CACT4Y+bcUggJkCFTYzT3PNgTtQb5i-uc3nHwixQp+nJORYk4RA@mail.gmail.com> (raw)
In-Reply-To: <0000000000009b403005942237bf@google.com>
On Sat, Oct 5, 2019 at 6:26 AM syzbot
<syzbot+c5d03165a1bd1dead0c1@syzkaller.appspotmail.com> wrote:
>
> 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
+Christian, you wanted races in process mgmt ;)
> ==================================================================
> 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. 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.
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000009b403005942237bf%40google.com.
next prev parent reply other threads:[~2019-10-05 4:29 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-05 4:26 KCSAN: data-race in taskstats_exit / taskstats_exit syzbot
2019-10-05 4:29 ` Dmitry Vyukov [this message]
2019-10-05 11:29 ` Christian Brauner
2019-10-05 11:28 ` [PATCH] taskstats: fix data-race Christian Brauner
2019-10-05 13:33 ` Marco Elver
2019-10-05 14:15 ` Christian Brauner
2019-10-05 14:34 ` Marco Elver
2019-10-06 10:00 ` Dmitry Vyukov
2019-10-06 10:59 ` Christian Brauner
2019-10-06 23:52 ` Christian Brauner
2019-10-07 7:31 ` Dmitry Vyukov
2019-10-07 9:29 ` Christian Brauner
2019-10-07 10:40 ` Andrea Parri
2019-10-07 10:50 ` Christian Brauner
2019-10-07 11:01 ` [PATCH v2] " Christian Brauner
2019-10-07 13:18 ` Andrea Parri
2019-10-07 13:28 ` Christian Brauner
2019-10-07 13:50 ` Dmitry Vyukov
2019-10-07 13:55 ` Christian Brauner
2019-10-07 14:08 ` Dmitry Vyukov
2019-10-07 14:10 ` Christian Brauner
2019-10-07 14:14 ` Andrea Parri
2019-10-07 14:18 ` Dmitry Vyukov
2019-10-08 14:20 ` Andrea Parri
2019-10-08 14:24 ` Christian Brauner
2019-10-08 15:26 ` Andrea Parri
2019-10-08 15:35 ` Christian Brauner
2019-10-08 15:44 ` Andrea Parri
2019-10-09 11:31 ` [PATCH] " Christian Brauner
2019-10-09 11:40 ` Christian Brauner
2019-10-09 11:48 ` [PATCH v5] " Christian Brauner
2019-10-09 12:08 ` Andrea Parri
2019-10-09 13:26 ` Christian Brauner
2019-10-21 11:33 ` [PATCH v6] " Christian Brauner
2019-10-21 12:19 ` Rasmus Villemoes
2019-10-21 13:04 ` Christian Brauner
2019-11-29 17:56 ` Will Deacon
2019-11-30 15:08 ` Christian Brauner
2019-10-23 12:16 ` Andrea Parri
2019-10-23 12:39 ` Dmitry Vyukov
2019-10-23 13:11 ` Christian Brauner
2019-10-23 13:20 ` Dmitry Vyukov
2019-10-24 11:31 ` Andrea Parri
2019-10-24 11:51 ` Dmitry Vyukov
2019-10-24 13:05 ` Andrea Parri
2019-10-24 13:13 ` Dmitry Vyukov
2019-10-24 13:21 ` Christian Brauner
2019-10-24 13:34 ` Dmitry Vyukov
2019-10-24 13:43 ` Andrea Parri
2019-10-24 13:58 ` Dmitry Vyukov
2019-10-24 14:40 ` Andrea Parri
2019-10-24 14:49 ` Dmitry Vyukov
2019-11-29 17:57 ` Will Deacon
2019-10-09 11:48 ` [PATCH] " Marco Elver
2019-10-09 11:53 ` Christian Brauner
2019-11-06 0:27 ` Balbir Singh
2019-11-06 0:09 ` KCSAN: data-race in taskstats_exit / taskstats_exit Balbir Singh
2019-11-06 10:23 ` Marco Elver
2019-11-07 10:39 ` Balbir Singh
2019-11-08 0:54 ` Balbir Singh
2019-11-08 8:55 ` Dmitry Vyukov
2019-11-09 3:42 ` Balbir Singh
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CACT4Y+bcUggJkCFTYzT3PNgTtQb5i-uc3nHwixQp+nJORYk4RA@mail.gmail.com \
--to=dvyukov@google.com \
--cc=bsingharora@gmail.com \
--cc=christian@brauner.io \
--cc=elver@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=syzbot+c5d03165a1bd1dead0c1@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).