syzbot


KCSAN: data-race in __tty_hangup / tty_hung_up_p (9)

Status: auto-closed as invalid on 2022/08/03 23:21
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 159d, last: 159d
similar bugs (8):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __tty_hangup / tty_hung_up_p (4) 3 559d 605d 0/24 auto-closed as invalid on 2021/06/30 05:54
upstream KCSAN: data-race in __tty_hangup / tty_hung_up_p (8) 1 326d 326d 0/24 auto-closed as invalid on 2022/02/17 20:31
upstream KCSAN: data-race in __tty_hangup / tty_hung_up_p (6) 1 417d 417d 0/24 auto-closed as invalid on 2021/11/19 04:32
upstream KCSAN: data-race in __tty_hangup / tty_hung_up_p 4 1081d 1100d 0/24 auto-closed as invalid on 2020/02/29 07:50
upstream KCSAN: data-race in __tty_hangup / tty_hung_up_p (3) 1 669d 669d 0/24 auto-closed as invalid on 2021/03/12 04:16
upstream KCSAN: data-race in __tty_hangup / tty_hung_up_p (7) 1 376d 376d 0/24 auto-closed as invalid on 2021/12/30 10:24
upstream KCSAN: data-race in __tty_hangup / tty_hung_up_p (5) 1 507d 507d 0/24 auto-closed as invalid on 2021/08/21 03:58
upstream KCSAN: data-race in __tty_hangup / tty_hung_up_p (2) 1 851d 851d 0/24 auto-closed as invalid on 2020/09/11 06:18

Sample crash report:
loop4: detected capacity change from 0 to 8
==================================================================
BUG: KCSAN: data-race in __tty_hangup / tty_hung_up_p

write to 0xffff888138df3828 of 8 bytes by task 22629 on cpu 0:
 __tty_hangup+0x22a/0x5b0 drivers/tty/tty_io.c:628
 tty_vhangup drivers/tty/tty_io.c:707 [inline]
 tty_ioctl+0x49f/0x970 drivers/tty/tty_io.c:2718
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read to 0xffff888138df3828 of 8 bytes by task 22628 on cpu 1:
 tty_hung_up_p+0x1c/0x40 drivers/tty/tty_io.c:752
 n_tty_poll+0x3f5/0x4a0 drivers/tty/n_tty.c:2384
 tty_poll+0xa3/0x120 drivers/tty/tty_io.c:2212
 vfs_poll include/linux/poll.h:88 [inline]
 __io_arm_poll_handler+0x1b9/0x570 fs/io_uring.c:7125
 io_arm_poll_handler+0x370/0x430 fs/io_uring.c:7229
 io_queue_async+0x7b/0x160 fs/io_uring.c:8688
 io_queue_sqe fs/io_uring.c:8726 [inline]
 io_submit_sqe+0x3998/0x3eb0 fs/io_uring.c:8977
 io_submit_sqes+0x27b/0x500 fs/io_uring.c:9088
 __do_sys_io_uring_enter fs/io_uring.c:12035 [inline]
 __se_sys_io_uring_enter+0x24b/0xd60 fs/io_uring.c:11961
 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:11961
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

value changed: 0xffffffff84eb80e0 -> 0xffffffff84eb7fd8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 22628 Comm: syz-executor.4 Not tainted 5.19.0-rc4-syzkaller-00036-gd9b2ba67917c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/06/29 23:16 upstream d9b2ba67917c 1434eec0 .config log report info KCSAN: data-race in __tty_hangup / tty_hung_up_p
* Struck through repros no longer work on HEAD.