syzbot


KCSAN: data-race in __tty_hangup / tty_hung_up_p (8)

Status: auto-closed as invalid on 2022/02/17 20:31
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 326d, last: 326d
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 (9) 1 159d 159d 0/24 auto-closed as invalid on 2022/08/03 23:21
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:
==================================================================
BUG: KCSAN: data-race in __tty_hangup / tty_hung_up_p

write to 0xffff888131afef28 of 8 bytes by task 15477 on cpu 1:
 __tty_hangup+0x23e/0x5f0 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+0x255/0xa00 drivers/tty/tty_io.c:1758
 __fput+0x295/0x520 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0x8e/0x110 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x160/0x190 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:300
 do_syscall_64+0x50/0xd0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888131afef28 of 8 bytes by task 15478 on cpu 0:
 tty_hung_up_p+0x1c/0x40 drivers/tty/tty_io.c:752
 n_tty_write+0x2b4/0xaf0 drivers/tty/n_tty.c:2244
 do_tty_write drivers/tty/tty_io.c:1024 [inline]
 file_tty_write+0x409/0x660 drivers/tty/tty_io.c:1095
 tty_write+0x24/0x30 drivers/tty/tty_io.c:1116
 call_write_iter include/linux/fs.h:2086 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x7f5/0x950 fs/read_write.c:590
 ksys_write+0xd9/0x190 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:652
 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

value changed: 0xffffffff84eab808 -> 0xffffffff84eab708

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15478 Comm: syz-executor.5 Not tainted 5.16.0-syzkaller #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 2022/01/13 20:22 upstream 455e73a07f6e b8d780ab .config log report info KCSAN: data-race in __tty_hangup / tty_hung_up_p
* Struck through repros no longer work on HEAD.