syzbot


KCSAN: data-race in __fput / __tty_hangup (3)

Status: auto-closed as invalid on 2022/08/23 04:41
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 159d, last: 141d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __fput / __tty_hangup (2) 1 196d 196d 0/24 auto-closed as invalid on 2022/06/29 01:31
upstream KCSAN: data-race in __fput / __tty_hangup 1 863d 863d 0/24 auto-closed as invalid on 2020/08/31 10:07

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __fput / __tty_hangup

write to 0xffff8881452ed528 of 8 bytes by task 30187 on cpu 1:
 __tty_hangup+0x22a/0x5b0 drivers/tty/tty_io.c:628
 tty_vhangup+0x13/0x20 drivers/tty/tty_io.c:707
 pty_close+0x25e/0x280 drivers/tty/pty.c:79
 tty_release+0x255/0x9d0 drivers/tty/tty_io.c:1758
 __fput+0x292/0x510 fs/file_table.c:317
 ____fput+0x11/0x20 fs/file_table.c:350
 task_work_run+0x8e/0x110 kernel/task_work.c:177
 get_signal+0xeca/0x1020 kernel/signal.c:2634
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop+0x78/0x130 kernel/entry/common.c:166
 exit_to_user_mode_prepare kernel/entry/common.c:201 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x6a/0x90 kernel/entry/common.c:294
 do_syscall_64+0x37/0x70 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff8881452ed528 of 8 bytes by task 30216 on cpu 0:
 __fput+0x263/0x510 fs/file_table.c:316
 ____fput+0x11/0x20 fs/file_table.c:350
 task_work_run+0x8e/0x110 kernel/task_work.c:177
 get_signal+0xeca/0x1020 kernel/signal.c:2634
 arch_do_signal_or_restart+0x87/0x2d0 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop+0x78/0x130 kernel/entry/common.c:166
 exit_to_user_mode_prepare kernel/entry/common.c:201 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x6a/0x90 kernel/entry/common.c:294
 do_syscall_64+0x37/0x70 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0xffffffff84eb8160 -> 0xffffffff84eb8058

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 30216 Comm: syz-executor.1 Not tainted 5.19.0-rc7-syzkaller-00002-g80e19f34c288-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/07/19 04:40 upstream 80e19f34c288 ff988920 .config log report info KCSAN: data-race in __fput / __tty_hangup
ci2-upstream-kcsan-gce 2022/07/01 04:25 upstream 1a0e93df1e10 1434eec0 .config log report info KCSAN: data-race in __fput / __tty_hangup
* Struck through repros no longer work on HEAD.