syzbot


KCSAN: data-race in io_cancel_task_cb / io_openat2

Status: auto-closed as invalid on 2021/02/24 22:17
Subsystems: fs
[Documentation on labels]
First crash: 1189d, last: 1189d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in io_cancel_task_cb / io_openat2

write to 0xffff88810ddc4358 of 4 bytes by task 13187 on cpu 0:
 io_openat2+0xe7/0x580 fs/io_uring.c:4124
 io_issue_sqe+0xba4/0x3f30 fs/io_uring.c:6314
 io_wq_submit_work+0x24c/0x4a0 fs/io_uring.c:6383
 io_worker_handle_work+0xd08/0x1070 fs/io-wq.c:565
 io_wqe_worker+0x211/0x880 fs/io-wq.c:607
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff88810ddc4358 of 4 bytes by task 13184 on cpu 1:
 io_cancel_task_cb+0x3d/0x330 fs/io_uring.c:8807
 io_wq_worker_cancel+0x73/0x130 fs/io-wq.c:948
 io_wq_for_each_worker+0x11c/0x230 fs/io-wq.c:743
 io_wqe_cancel_running_work fs/io-wq.c:1005 [inline]
 io_wq_cancel_cb+0x448/0x530 fs/io-wq.c:1041
 io_uring_cancel_files fs/io_uring.c:8874 [inline]
 io_uring_cancel_task_requests fs/io_uring.c:8952 [inline]
 __io_uring_files_cancel+0x8c0/0xce0 fs/io_uring.c:9038
 io_uring_files_cancel include/linux/io_uring.h:51 [inline]
 do_exit+0x19a/0x1690 kernel/exit.c:780
 do_group_exit+0xc8/0x170 kernel/exit.c:922
 get_signal+0xd7e/0x1470 kernel/signal.c:2773
 arch_do_signal_or_restart+0x2a/0x270 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x109/0x1a0 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13184 Comm: syz-executor.5 Not tainted 5.11.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/01/20 22:16 upstream 75439bc439e0 d4f4eca5 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in io_cancel_task_cb / io_openat2
* Struck through repros no longer work on HEAD.