syzbot


KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common

Status: auto-closed as invalid on 2020/04/15 15:43
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 1089d, last: 1089d
similar bugs (6):
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 276d 276d 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 480d 502d 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 196d 196d 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 (3) 4 349d 399d 0/24 auto-closed as invalid on 2022/03/21 13:14
upstream KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common (7) 2 57d 66d 0/24 auto-obsoleted due to no activity on 2023/01/17 00:23
upstream KCSAN: data-race in n_tty_kick_worker / n_tty_receive_buf_common (6) 1 120d 120d 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 0xffffc900011a905c of 1 bytes by task 8745 on cpu 0:
 n_tty_kick_worker+0x3c/0x170 drivers/tty/n_tty.c:209
 n_tty_check_unthrottle drivers/tty/n_tty.c:280 [inline]
 n_tty_read+0x989/0x12b0 drivers/tty/n_tty.c:2259
 tty_read+0x11d/0x1c0 drivers/tty/tty_io.c:869
 __vfs_read+0x67/0xc0 fs/read_write.c:425
 vfs_read fs/read_write.c:461 [inline]
 vfs_read+0x143/0x2c0 fs/read_write.c:446
 ksys_read+0xd5/0x1b0 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffffc900011a905c of 1 bytes by task 31657 on cpu 1:
 n_tty_receive_buf_common+0x1362/0x1b00 drivers/tty/n_tty.c:1732
 n_tty_receive_buf2+0x3d/0x60 drivers/tty/n_tty.c:1777
 tty_ldisc_receive_buf+0x71/0xf0 drivers/tty/tty_buffer.c:461
 tty_port_default_receive_buf+0x87/0xd0 drivers/tty/tty_port.c:38
 receive_buf drivers/tty/tty_buffer.c:481 [inline]
 flush_to_ldisc+0x1d5/0x260 drivers/tty/tty_buffer.c:533
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2264
 worker_thread+0xa0/0x800 kernel/workqueue.c:2410
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 31657 Comm: kworker/u4:4 Not tainted 5.5.0-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):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-upstream-kcsan-gce 2020/02/05 15:40 https://github.com/google/ktsan.git kcsan 245a43005292 662cf49a .config console log report
* Struck through repros no longer work on HEAD.