syzbot


KCSAN: data-race in __tty_hangup / filp_close

Status: auto-closed as invalid on 2022/06/01 05:00
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 215d, last: 215d

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

write to 0xffff88813904ea28 of 8 bytes by task 7614 on cpu 0:
 __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:164
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0x124/0x130 kernel/entry/common.c:169
 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+0x44/0xae

read to 0xffff88813904ea28 of 8 bytes by task 7597 on cpu 1:
 filp_close+0x42/0xf0 fs/open.c:1322
 do_dup2+0x224/0x240 fs/file.c:1140
 ksys_dup3+0x157/0x1d0 fs/file.c:1257
 __do_sys_dup3 fs/file.c:1268 [inline]
 __se_sys_dup3 fs/file.c:1266 [inline]
 __x64_sys_dup3+0x3b/0x50 fs/file.c:1266
 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+0x44/0xae

value changed: 0xffffffff84eaf6b8 -> 0xffffffff84eaf5b8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7597 Comm: syz-executor.3 Not tainted 5.18.0-rc4-syzkaller-00036-gcf424ef014ac-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 2022/04/27 04:59 upstream cf424ef014ac 1fa34c1b .config log report info KCSAN: data-race in __tty_hangup / filp_close
* Struck through repros no longer work on HEAD.