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KCSAN: data-race in n_tty_write / tty_set_termios (4)

Status: auto-closed as invalid on 2021/03/04 08:49
Subsystems: serial
[Documentation on labels]
First crash: 1230d, last: 1179d
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in n_tty_write / tty_set_termios (3) serial 1 1271d 1271d 0/26 auto-closed as invalid on 2020/12/02 18:50
upstream KCSAN: data-race in n_tty_write / tty_set_termios (10) serial 1 368d 368d 0/26 auto-obsoleted due to no activity on 2023/05/24 17:53
upstream KCSAN: data-race in n_tty_write / tty_set_termios (8) serial 9 612d 738d 0/26 auto-closed as invalid on 2022/09/22 18:33
upstream KCSAN: data-race in n_tty_write / tty_set_termios (2) serial 1 1335d 1335d 0/26 auto-closed as invalid on 2020/09/29 07:57
upstream KCSAN: data-race in n_tty_write / tty_set_termios (6) serial 8 898d 1016d 0/26 auto-closed as invalid on 2021/12/10 21:01
upstream KCSAN: data-race in n_tty_write / tty_set_termios (5) serial 2 1069d 1071d 0/26 auto-closed as invalid on 2021/06/22 15:42
upstream KCSAN: data-race in n_tty_write / tty_set_termios serial 1 1397d 1397d 0/26 auto-closed as invalid on 2020/07/29 04:13
upstream KCSAN: data-race in n_tty_write / tty_set_termios (7) serial 4 780d 817d 0/26 auto-closed as invalid on 2022/04/07 21:37
upstream KCSAN: data-race in n_tty_write / tty_set_termios (9) serial 7 459d 540d 0/26 auto-obsoleted due to no activity on 2023/02/26 21:46

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

read-write to 0xffff8881078f911c of 4 bytes by task 8152 on cpu 0:
 unset_locked_termios drivers/tty/tty_ioctl.c:254 [inline]
 tty_set_termios+0x1a3/0x870 drivers/tty/tty_ioctl.c:331
 set_termios+0x375/0x3b0 drivers/tty/tty_ioctl.c:414
 tty_mode_ioctl+0x57c/0x680 drivers/tty/tty_ioctl.c:725
 n_tty_ioctl_helper+0x8b/0x460 drivers/tty/tty_ioctl.c:883
 n_tty_ioctl+0x102/0x200 drivers/tty/n_tty.c:2465
 tty_ioctl+0xa9f/0x1030 drivers/tty/tty_io.c:2670
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8881078f911c of 4 bytes by task 18977 on cpu 1:
 n_tty_write+0x86/0xae0 drivers/tty/n_tty.c:2309
 do_tty_write drivers/tty/tty_io.c:961 [inline]
 tty_write+0x3e9/0x630 drivers/tty/tty_io.c:1049
 call_write_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4b0 fs/read_write.c:866
 vfs_writev fs/read_write.c:939 [inline]
 do_writev+0x201/0x460 fs/read_write.c:982
 __do_sys_writev fs/read_write.c:1055 [inline]
 __se_sys_writev fs/read_write.c:1052 [inline]
 __x64_sys_writev+0x41/0x50 fs/read_write.c:1052
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 18977 Comm: syz-executor.3 Not tainted 5.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/01/28 08:46 upstream 76c057c84d28 eefc07f2 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_write / tty_set_termios
2021/01/08 17:25 upstream f5e6c330254a c104d4a3 .config console log report info ci2-upstream-kcsan-gce
2020/12/08 22:04 upstream 7d8761ba27fc 40cc414d .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.