Hello, syzbot found the following issue on: HEAD commit: 86cfccb6 Merge tag 'dlm-5.9' of git://git.kernel.org/pub/s.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=171cf11a900000 kernel config: https://syzkaller.appspot.com/x/.config?x=3757fa75ecfde8e0 dashboard link: https://syzkaller.appspot.com/bug?extid=3020eb77f81ef0772fbe compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b) Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+3020eb77f81ef0772fbe@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KCSAN: data-race in __io_cqring_fill_event / io_uring_poll write to 0xffff8880a04325c0 of 4 bytes by task 12088 on cpu 1: io_get_cqring fs/io_uring.c:1282 [inline] __io_cqring_fill_event+0x116/0x430 fs/io_uring.c:1386 io_cqring_add_event fs/io_uring.c:1420 [inline] __io_req_complete+0xdb/0x1b0 fs/io_uring.c:1458 io_complete_rw_common fs/io_uring.c:2208 [inline] __io_complete_rw+0x2c9/0x2e0 fs/io_uring.c:2289 kiocb_done fs/io_uring.c:2533 [inline] io_write fs/io_uring.c:3199 [inline] io_issue_sqe+0x4fb1/0x7140 fs/io_uring.c:5530 io_wq_submit_work+0x23e/0x340 fs/io_uring.c:5775 io_worker_handle_work+0xa69/0xcf0 fs/io-wq.c:527 io_wqe_worker+0x1f2/0x860 fs/io-wq.c:569 kthread+0x20d/0x230 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 read to 0xffff8880a04325c0 of 4 bytes by task 12086 on cpu 0: io_cqring_events fs/io_uring.c:1937 [inline] io_uring_poll+0x105/0x140 fs/io_uring.c:7751 vfs_poll include/linux/poll.h:90 [inline] __io_arm_poll_handler+0x176/0x3f0 fs/io_uring.c:4735 io_arm_poll_handler+0x293/0x5c0 fs/io_uring.c:4792 __io_queue_sqe+0x413/0x760 fs/io_uring.c:5988 io_queue_sqe+0x81/0x2b0 fs/io_uring.c:6060 io_submit_sqe+0x333/0x560 fs/io_uring.c:6130 io_submit_sqes+0x8c6/0xfc0 fs/io_uring.c:6327 __do_sys_io_uring_enter fs/io_uring.c:8036 [inline] __se_sys_io_uring_enter+0x1c2/0x720 fs/io_uring.c:7995 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:7995 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 12086 Comm: syz-executor.5 Not tainted 5.8.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== --- 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.
