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KCSAN: data-race in __stop_tty / pty_write

Status: auto-closed as invalid on 2021/08/19 13:20
Subsystems: serial
[Documentation on labels]
First crash: 1069d, last: 1069d
Similar bugs (12)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __stop_tty / pty_write (6) serial 1 762d 762d 0/27 auto-closed as invalid on 2022/06/22 11:40
upstream KCSAN: data-race in __stop_tty / pty_write (8) serial 4 422d 438d 0/27 auto-obsoleted due to no activity on 2023/05/28 07:29
upstream KCSAN: data-race in __stop_tty / pty_write (9) serial 3 332d 362d 0/27 auto-obsoleted due to no activity on 2023/08/26 21:27
upstream KCSAN: data-race in __stop_tty / pty_write (2) serial 1 987d 987d 0/27 auto-closed as invalid on 2021/11/09 20:04
upstream KCSAN: data-race in __stop_tty / pty_write (4) serial 1 859d 859d 0/27 auto-closed as invalid on 2022/03/17 12:14
upstream KCSAN: data-race in __stop_tty / pty_write (3) serial 1 946d 946d 0/27 auto-closed as invalid on 2021/12/20 07:00
upstream KCSAN: data-race in __stop_tty / pty_write (13) serial 13 3h45m 90d 0/27 moderation: reported on 2024/03/20 09:24
upstream KCSAN: data-race in __stop_tty / pty_write (5) serial 1 815d 815d 0/27 auto-closed as invalid on 2022/04/30 10:57
upstream KCSAN: data-race in __stop_tty / pty_write (10) serial 1 283d 283d 0/27 auto-obsoleted due to no activity on 2023/10/14 11:29
upstream KCSAN: data-race in __stop_tty / pty_write (11) serial 3 240d 242d 0/27 auto-obsoleted due to no activity on 2023/11/26 18:07
upstream KCSAN: data-race in __stop_tty / pty_write (12) serial 7 127d 188d 0/27 auto-obsoleted due to no activity on 2024/03/18 19:09
upstream KCSAN: data-race in __stop_tty / pty_write (7) serial 1 621d 621d 0/27 auto-obsoleted due to no activity on 2022/11/10 14:49

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

write to 0xffff88812d3825bc of 1 bytes by task 15668 on cpu 1:
 __stop_tty+0x3e/0x80 drivers/tty/tty_io.c:768
 n_tty_ioctl_helper+0x333/0x4c0 drivers/tty/tty_ioctl.c:876
 n_tty_ioctl+0x102/0x200 drivers/tty/n_tty.c:2421
 tty_ioctl+0xa8f/0x1120 drivers/tty/tty_io.c:2814
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:1055
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:1055
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812d3825bc of 1 bytes by task 5418 on cpu 0:
 pty_write+0x38/0x120 drivers/tty/pty.c:116
 tty_put_char+0x7f/0xa0 drivers/tty/tty_io.c:3174
 __process_echoes+0x3bd/0x660 drivers/tty/n_tty.c:726
 commit_echoes drivers/tty/n_tty.c:791 [inline]
 n_tty_receive_char+0x649/0x6c0 drivers/tty/n_tty.c:1411
 n_tty_receive_buf_standard drivers/tty/n_tty.c:1560 [inline]
 __receive_buf drivers/tty/n_tty.c:1577 [inline]
 n_tty_receive_buf_common+0xf2e/0x4e70 drivers/tty/n_tty.c:1674
 n_tty_receive_buf2+0x2e/0x40 drivers/tty/n_tty.c:1709
 tty_ldisc_receive_buf+0x5b/0xf0 drivers/tty/tty_buffer.c:471
 tty_port_default_receive_buf+0x54/0x80 drivers/tty/tty_port.c:39
 receive_buf drivers/tty/tty_buffer.c:491 [inline]
 flush_to_ldisc+0x1c5/0x2c0 drivers/tty/tty_buffer.c:543
 process_one_work+0x3e9/0x8f0 kernel/workqueue.c:2276
 worker_thread+0x636/0xae0 kernel/workqueue.c:2422
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5418 Comm: kworker/u4:7 Not tainted 5.14.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound flush_to_ldisc
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/07/15 13:13 upstream 8096acd7442e b9a2f64e .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / pty_write
* Struck through repros no longer work on HEAD.