syzbot


KCSAN: data-race in n_tty_poll / tty_set_termios (6)

Status: auto-obsoleted due to no activity on 2024/03/08 03:04
Subsystems: serial
[Documentation on labels]
Reported-by: syzbot+3419ff8d88a24e6515cb@syzkaller.appspotmail.com
First crash: 71d, last: 71d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in n_tty_poll / tty_set_termios (4) serial 1 824d 824d 0/26 auto-closed as invalid on 2022/02/14 10:19
upstream KCSAN: data-race in n_tty_poll / tty_set_termios (2) serial 2 1015d 1049d 0/26 auto-closed as invalid on 2021/08/07 13:54
upstream KCSAN: data-race in n_tty_poll / tty_set_termios serial 1 1092d 1092d 0/26 auto-closed as invalid on 2021/05/22 11:20
upstream KCSAN: data-race in n_tty_poll / tty_set_termios (5) serial 1 214d 214d 0/26 auto-obsoleted due to no activity on 2023/10/17 08:33
upstream KCSAN: data-race in n_tty_poll / tty_set_termios (3) serial 1 905d 905d 0/26 auto-closed as invalid on 2021/11/25 02:42

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

write to 0xffff888137e6a91e of 1 bytes by task 5945 on cpu 1:
 unset_locked_termios drivers/tty/tty_ioctl.c:220 [inline]
 tty_set_termios+0x3a4/0x8a0 drivers/tty/tty_ioctl.c:340
 set_termios+0x47e/0x4c0 drivers/tty/tty_ioctl.c:516
 tty_mode_ioctl+0x391/0x5d0
 n_tty_ioctl_helper+0x8d/0x240 drivers/tty/tty_ioctl.c:986
 n_tty_ioctl+0xfd/0x200 drivers/tty/n_tty.c:2511
 tty_ioctl+0x875/0xbc0 drivers/tty/tty_io.c:2812
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl+0xcf/0x140 fs/ioctl.c:857
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888137e6a91e of 1 bytes by task 9 on cpu 0:
 input_available_p drivers/tty/n_tty.c:1927 [inline]
 n_tty_poll+0x217/0x490 drivers/tty/n_tty.c:2458
 tty_poll+0x7b/0xf0 drivers/tty/tty_io.c:2214
 vfs_poll include/linux/poll.h:88 [inline]
 p9_fd_poll net/9p/trans_fd.c:237 [inline]
 p9_poll_mux net/9p/trans_fd.c:629 [inline]
 p9_poll_workfn+0x1e9/0x410 net/9p/trans_fd.c:1178
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x5b8/0xa40 kernel/workqueue.c:2706
 worker_thread+0x525/0x730 kernel/workqueue.c:2787
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

value changed: 0x79 -> 0xf2

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.8.0-rc2-syzkaller-00084-g5c24e4e9e708 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: events p9_poll_workfn
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/02 03:03 upstream 5c24e4e9e708 d61103fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_poll / tty_set_termios
* Struck through repros no longer work on HEAD.