syzbot


KCSAN: data-race in __tty_hangup / vfs_read

Status: auto-closed as invalid on 2021/11/13 08:12
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 416d, last: 416d

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

write to 0xffff88813d424828 of 8 bytes by task 10305 on cpu 1:
 __tty_hangup+0x247/0x650 drivers/tty/tty_io.c:630
 tty_vhangup+0x13/0x20 drivers/tty/tty_io.c:711
 pty_close+0x27b/0x2a0 drivers/tty/pty.c:79
 tty_release+0x255/0xa10 drivers/tty/tty_io.c:1771
 __fput+0x295/0x520 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0xae/0x130 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+0x156/0x190 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+0x50/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813d424828 of 8 bytes by task 10335 on cpu 0:
 vfs_read+0x1b6/0x750 fs/read_write.c:482
 ksys_read+0xd9/0x190 fs/read_write.c:623
 __do_sys_read fs/read_write.c:633 [inline]
 __se_sys_read fs/read_write.c:631 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:631
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffffffff8308b4d8 -> 0xffffffff8308b3d8

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10335 Comm: syz-executor.4 Not tainted 5.15.0-rc4-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 2021/10/09 08:03 upstream 741668ef7832 efe0f24d .config log report info KCSAN: data-race in __tty_hangup / vfs_read
* Struck through repros no longer work on HEAD.