syzbot


KCSAN: data-race in __tty_hangup / io_arm_poll_handler

Status: auto-obsoleted due to no activity on 2023/12/25 00:09
Subsystems: serial
[Documentation on labels]
Reported-by: syzbot+74c859f8d6a768d0c7a4@syzkaller.appspotmail.com
First crash: 103d, last: 103d

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

write to 0xffff88814c1ab5b0 of 8 bytes by task 28997 on cpu 0:
 __tty_hangup+0x1e8/0x530 drivers/tty/tty_io.c:621
 tty_vhangup+0x17/0x20 drivers/tty/tty_io.c:700
 pty_close+0x262/0x280 drivers/tty/pty.c:79
 tty_release+0x204/0x930 drivers/tty/tty_io.c:1756
 __fput+0x299/0x630 fs/file_table.c:394
 ____fput+0x15/0x20 fs/file_table.c:422
 task_work_run+0x135/0x1a0 kernel/task_work.c:180
 get_signal+0xf04/0x10a0 kernel/signal.c:2680
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:309
 exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
 do_syscall_64+0x50/0x110 arch/x86/entry/common.c:88
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88814c1ab5b0 of 8 bytes by task 29003 on cpu 1:
 file_can_poll include/linux/poll.h:81 [inline]
 io_arm_poll_handler+0xb5/0x580 io_uring/poll.c:709
 io_queue_async+0x85/0x470 io_uring/io_uring.c:2048
 io_queue_sqe io_uring/io_uring.c:2079 [inline]
 io_req_task_submit+0x11c/0x130 io_uring/io_uring.c:1498
 handle_tw_list io_uring/io_uring.c:1207 [inline]
 tctx_task_work+0x1af/0x4c0 io_uring/io_uring.c:1299
 task_work_run+0x135/0x1a0 kernel/task_work.c:180
 get_signal+0xf04/0x10a0 kernel/signal.c:2680
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:309
 exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
 do_syscall_64+0x50/0x110 arch/x86/entry/common.c:88
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0xffffffff84e96138 -> 0xffffffff84e95fd0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29003 Comm: syz-executor.3 Tainted: G        W          6.7.0-rc1-syzkaller-00012-g9bacdd8996c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/15 00:47 upstream 9bacdd8996c7 cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __tty_hangup / io_arm_poll_handler
* Struck through repros no longer work on HEAD.