syzbot


KCSAN: data-race in __tty_hangup / do_dentry_open (5)

Status: moderation: reported on 2024/09/22 16:47
Subsystems: serial
[Documentation on labels]
Reported-by: syzbot+47f7dcc37ee28d91b0fb@syzkaller.appspotmail.com
First crash: 5d22h, last: 5d22h
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __tty_hangup / do_dentry_open (4) serial 1 243d 243d 0/28 auto-obsoleted due to no activity on 2024/03/04 05:22
upstream KCSAN: data-race in __tty_hangup / do_dentry_open serial 1 1340d 1340d 0/28 auto-closed as invalid on 2021/03/02 15:38
upstream KCSAN: data-race in __tty_hangup / do_dentry_open (2) serial 1 840d 840d 0/28 auto-closed as invalid on 2022/07/16 05:33
upstream KCSAN: data-race in __tty_hangup / do_dentry_open (3) serial 1 756d 756d 0/28 auto-obsoleted due to no activity on 2022/10/07 18:15

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

write to 0xffff888103e0fcd0 of 8 bytes by task 27189 on cpu 1:
 __tty_hangup+0x1d6/0x530 drivers/tty/tty_io.c:621
 tty_vhangup drivers/tty/tty_io.c:700 [inline]
 tty_ioctl+0x607/0xbe0 drivers/tty/tty_io.c:2749
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xcd/0x140 fs/ioctl.c:893
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:893
 x64_sys_call+0x15cc/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888103e0fcd0 of 8 bytes by task 27190 on cpu 0:
 do_dentry_open+0x692/0xa20 fs/open.c:964
 vfs_open+0x38/0x1f0 fs/open.c:1088
 do_open fs/namei.c:3774 [inline]
 path_openat+0x1ac2/0x1fa0 fs/namei.c:3933
 do_filp_open+0xf7/0x200 fs/namei.c:3960
 do_sys_openat2+0xab/0x120 fs/open.c:1415
 do_sys_open fs/open.c:1430 [inline]
 __do_sys_openat fs/open.c:1446 [inline]
 __se_sys_openat fs/open.c:1441 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1441
 x64_sys_call+0x1025/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffffffff8569c898 -> 0xffffffff8569c730

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 27190 Comm: syz.0.5367 Not tainted 6.11.0-syzkaller-08481-g88264981f208 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/22 16:46 upstream 88264981f208 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __tty_hangup / do_dentry_open
* Struck through repros no longer work on HEAD.