syzbot


KCSAN: data-race in __io_commit_cqring_flush / io_submit_sqes

Status: moderation: reported on 2024/06/07 11:45
Subsystems: io-uring
[Documentation on labels]
Reported-by: syzbot+f99c8b5c962def815ea1@syzkaller.appspotmail.com
First crash: 7d18h, last: 7d18h

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __io_commit_cqring_flush / io_submit_sqes

read-write to 0xffff888131ecb004 of 2 bytes by task 15551 on cpu 0:
 io_init_req_drain io_uring/io_uring.c:2022 [inline]
 io_init_req io_uring/io_uring.c:2081 [inline]
 io_submit_sqe io_uring/io_uring.c:2182 [inline]
 io_submit_sqes+0xb7a/0x1070 io_uring/io_uring.c:2335
 __do_sys_io_uring_enter io_uring/io_uring.c:3244 [inline]
 __se_sys_io_uring_enter+0x1c6/0x15a0 io_uring/io_uring.c:3181
 __x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3181
 x64_sys_call+0x25ab/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:427
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888131ecb004 of 2 bytes by task 15554 on cpu 1:
 __io_commit_cqring_flush+0x20/0x1c0 io_uring/io_uring.c:624
 io_commit_cqring_flush io_uring/io_uring.h:364 [inline]
 io_cq_unlock_post io_uring/io_uring.c:668 [inline]
 io_req_complete_post io_uring/io_uring.c:939 [inline]
 io_issue_sqe+0x8d6/0xc80 io_uring/io_uring.c:1763
 io_wq_submit_work+0x42b/0x5a0 io_uring/io_uring.c:1860
 io_worker_handle_work+0x45a/0x9a0 io_uring/io-wq.c:597
 io_wq_worker+0x286/0x820 io_uring/io-wq.c:651
 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: 0x0100 -> 0x0109

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 15554 Comm: iou-wrk-15551 Not tainted 6.10.0-rc2-syzkaller-00235-g8a92980606e3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/07 11:44 upstream 8a92980606e3 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __io_commit_cqring_flush / io_submit_sqes
* Struck through repros no longer work on HEAD.