KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common

Status: closed as invalid on 2020/06/18 14:24
Subsystems: serial
[Documentation on labels]
First crash: 2484d, last: 2255d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common (2) serial 6 87 1833d 2073d 0/29 auto-closed as invalid on 2021/09/09 03:56

Sample crash report:
==================================================================
BUG: KCSAN: data-race in n_tty_receive_buf_common / n_tty_receive_buf_common

write to 0xffffc90003f2d020 of 8 bytes by task 19736 on cpu 1:
 flush_echoes drivers/tty/n_tty.c:828 [inline]
 __receive_buf drivers/tty/n_tty.c:1648 [inline]
 n_tty_receive_buf_common+0xda2/0x1a40 drivers/tty/n_tty.c:1742
 n_tty_receive_buf+0x36/0x50 drivers/tty/n_tty.c:1771
 tiocsti drivers/tty/tty_io.c:2196 [inline]
 tty_ioctl+0xaf4/0xd80 drivers/tty/tty_io.c:2572
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x101/0x150 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x47/0x60 fs/ioctl.c:770
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffffc90003f2d020 of 8 bytes by task 8470 on cpu 0:
 flush_echoes drivers/tty/n_tty.c:824 [inline]
 __receive_buf drivers/tty/n_tty.c:1648 [inline]
 n_tty_receive_buf_common+0xd5a/0x1a40 drivers/tty/n_tty.c:1742
 n_tty_receive_buf2+0x39/0x50 drivers/tty/n_tty.c:1777
 tty_ldisc_receive_buf+0x69/0xe0 drivers/tty/tty_buffer.c:461
 tty_port_default_receive_buf+0x82/0xd0 drivers/tty/tty_port.c:38
 receive_buf drivers/tty/tty_buffer.c:481 [inline]
 flush_to_ldisc+0x1dd/0x260 drivers/tty/tty_buffer.c:533
 process_one_work+0x424/0x930 kernel/workqueue.c:2268
 worker_thread+0x9a/0x7e0 kernel/workqueue.c:2414
 kthread+0x203/0x230 kernel/kthread.c:268
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8470 Comm: kworker/u4:1 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound flush_to_ldisc
==================================================================

Crashes (19):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/08 06:26 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 7751efd0 .config console log report ci2-upstream-kcsan-gce
2020/05/31 18:27 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a0331e89 .config console log report ci2-upstream-kcsan-gce
2020/05/27 01:11 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 9072c126 .config console log report ci2-upstream-kcsan-gce
2020/05/12 07:01 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a497a5b4 .config console log report ci2-upstream-kcsan-gce
2020/04/16 07:05 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 c743fcb3 .config console log report ci2-upstream-kcsan-gce
2020/04/04 06:18 https://github.com/google/ktsan.git kcsan 40959e34d670 ef26b610 .config console log report ci2-upstream-kcsan-gce
2020/03/18 22:07 https://github.com/google/ktsan.git kcsan 941e0d917bbf 0a96a13c .config console log report ci2-upstream-kcsan-gce
2020/03/12 09:12 https://github.com/google/ktsan.git kcsan 941e0d917bbf d850e9d0 .config console log report ci2-upstream-kcsan-gce
2020/03/08 00:07 https://github.com/google/ktsan.git kcsan 941e0d917bbf 2e9971bb .config console log report ci2-upstream-kcsan-gce
2020/02/29 02:15 https://github.com/google/ktsan.git kcsan 766d004d1b85 c88c7b75 .config console log report ci2-upstream-kcsan-gce
2020/02/26 15:02 https://github.com/google/ktsan.git kcsan 766d004d1b85 251aabb7 .config console log report ci2-upstream-kcsan-gce
2020/01/23 21:11 https://github.com/google/ktsan.git kcsan 245a43005292 11ebf937 .config console log report ci2-upstream-kcsan-gce
2020/01/07 13:30 https://github.com/google/ktsan.git kcsan 245a43005292 1bcd407e .config console log report ci2-upstream-kcsan-gce
2019/12/17 01:49 https://github.com/google/ktsan.git kcsan 245a43005292 d13d7958 .config console log report ci2-upstream-kcsan-gce
2019/12/14 07:33 https://github.com/google/ktsan.git kcsan 245a43005292 eef6e580 .config console log report ci2-upstream-kcsan-gce
2019/12/04 14:59 https://github.com/google/ktsan.git kcsan ef798c30ba4e b2088328 .config console log report ci2-upstream-kcsan-gce
2019/11/19 12:22 https://github.com/google/ktsan.git kcsan 5863cc791e4c 432c7650 .config console log report ci2-upstream-kcsan-gce
2019/11/03 22:06 https://github.com/google/ktsan.git kcsan 05f2236801fe b35fad31 .config console log report ci2-upstream-kcsan-gce
2019/10/23 18:48 https://github.com/google/ktsan.git kcsan 05f2236801fe b602d64b .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.