syzbot


KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common (3)

Status: auto-closed as invalid on 2022/03/21 13:14
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 341d, last: 291d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common (4) 1 219d 219d 0/24 auto-closed as invalid on 2022/06/02 02:02
upstream KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common (2) 4 422d 444d 0/24 auto-closed as invalid on 2021/11/10 16:29
upstream KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common (5) 1 138d 138d 0/24 auto-closed as invalid on 2022/08/21 08:44
upstream KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common 1 1031d 1031d 0/24 auto-closed as invalid on 2020/04/15 15:43
upstream KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common (6) 1 62d 62d 0/24 auto-obsoleted due to no activity on 2022/11/05 11:00

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

read to 0xffffc900081fd05c of 1 bytes by task 15579 on cpu 0:
 n_tty_kick_worker+0x2d/0x160 drivers/tty/n_tty.c:204
 n_tty_read+0xfbc/0x1070 drivers/tty/n_tty.c:2186
 iterate_tty_read drivers/tty/tty_io.c:858 [inline]
 tty_read+0x19c/0x430 drivers/tty/tty_io.c:933
 call_read_iter include/linux/fs.h:2068 [inline]
 do_iter_readv_writev+0x2fb/0x380 fs/read_write.c:723
 do_iter_read+0x192/0x5d0 fs/read_write.c:786
 vfs_readv fs/read_write.c:906 [inline]
 do_readv+0x171/0x2c0 fs/read_write.c:943
 __do_sys_readv fs/read_write.c:1034 [inline]
 __se_sys_readv fs/read_write.c:1031 [inline]
 __x64_sys_readv+0x41/0x50 fs/read_write.c:1031
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

write to 0xffffc900081fd05c of 1 bytes by task 15573 on cpu 1:
 n_tty_receive_buf_common+0x370/0x4e70 drivers/tty/n_tty.c:1635
 n_tty_receive_buf2+0x2e/0x40 drivers/tty/n_tty.c:1680
 tty_ldisc_receive_buf+0x5b/0xf0 drivers/tty/tty_buffer.c:451
 tty_port_default_receive_buf+0x54/0x80 drivers/tty/tty_port.c:39
 receive_buf drivers/tty/tty_buffer.c:471 [inline]
 flush_to_ldisc+0x1c5/0x300 drivers/tty/tty_buffer.c:521
 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307
 worker_thread+0x616/0xa70 kernel/workqueue.c:2454
 kthread+0x1bf/0x1e0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30

value changed: 0x01 -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 15573 Comm: kworker/u4:127 Not tainted 5.17.0-rc4-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound flush_to_ldisc
==================================================================

Crashes (4):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/02/14 13:12 upstream 754e0b0e3560 8b9ca619 .config log report info KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common
ci2-upstream-kcsan-gce 2022/01/31 08:42 upstream 26291c54e111 a491ad2d .config log report info KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common
ci2-upstream-kcsan-gce 2022/01/28 22:21 upstream df0001545b27 495e00c5 .config log report info KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common
ci2-upstream-kcsan-gce 2021/12/26 15:14 upstream 438645193e59 e4f103c4 .config log report info KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common
* Struck through repros no longer work on HEAD.