Hello, syzbot found the following issue on: HEAD commit: a5dbd76a8942 Merge tag 'x86-urgent-2024-08-04' of git://gi.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13d5a373980000 kernel config: https://syzkaller.appspot.com/x/.config?x=d16924117a4f7e9 dashboard link: https://syzkaller.appspot.com/bug?extid=b3e4f2f51ed645fd5df2 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/ba663ad5dbf5/disk-a5dbd76a.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/226a427d6581/vmlinux-a5dbd76a.xz kernel image: https://storage.googleapis.com/syzbot-assets/9f982777516a/bzImage-a5dbd76a.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b3e4f2f51ed645fd5df2@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KCSAN: data-race in __flush_work / __flush_work write to 0xffff8881223aa3e8 of 8 bytes by task 3998 on cpu 0: instrument_write include/linux/instrumented.h:41 [inline] ___set_bit include/asm-generic/bitops/instrumented-non-atomic.h:28 [inline] insert_wq_barrier kernel/workqueue.c:3790 [inline] start_flush_work kernel/workqueue.c:4142 [inline] __flush_work+0x30b/0x570 kernel/workqueue.c:4178 flush_work kernel/workqueue.c:4229 [inline] flush_delayed_work+0x66/0x70 kernel/workqueue.c:4251 io_fallback_tw+0x24b/0x320 io_uring/io_uring.c:1087 tctx_task_work_run+0xd1/0x1b0 io_uring/io_uring.c:1099 tctx_task_work+0x40/0x80 io_uring/io_uring.c:1124 task_work_run+0x13a/0x1a0 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x5dd/0x1720 kernel/exit.c:882 do_group_exit+0x102/0x150 kernel/exit.c:1031 get_signal+0xf2f/0x1080 kernel/signal.c:2917 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff8881223aa3e8 of 8 bytes by task 50 on cpu 1: __flush_work+0x42a/0x570 kernel/workqueue.c:4188 flush_work kernel/workqueue.c:4229 [inline] flush_delayed_work+0x66/0x70 kernel/workqueue.c:4251 io_uring_try_cancel_requests+0x35b/0x370 io_uring/io_uring.c:3000 io_ring_exit_work+0x148/0x500 io_uring/io_uring.c:2779 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312 worker_thread+0x526/0x700 kernel/workqueue.c:3390 kthread+0x1d1/0x210 kernel/kthread.c:389 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 value changed: 0x0000000000400000 -> 0xffff88810006c00d Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 50 Comm: kworker/u8:3 Not tainted 6.11.0-rc1-syzkaller-00334-ga5dbd76a8942 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: iou_exit io_ring_exit_work ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
