syzbot


KCSAN: data-race in __io_fill_cqe_req / io_cqring_wait

Status: auto-closed as invalid on 2022/05/03 11:08
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 249d, last: 249d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __io_fill_cqe_req / io_cqring_wait (2) 1 143d 143d 0/24 auto-closed as invalid on 2022/08/16 16:26

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __io_fill_cqe_req / io_cqring_wait

write to 0xffff888127e5ba00 of 4 bytes by task 13674 on cpu 0:
 io_get_cqe fs/io_uring.c:1846 [inline]
 __io_fill_cqe fs/io_uring.c:2056 [inline]
 __io_fill_cqe_req+0x129/0x3a0 fs/io_uring.c:2069
 __io_req_complete_post+0x59/0x410 fs/io_uring.c:2092
 io_req_complete_post fs/io_uring.c:2120 [inline]
 io_req_complete_failed+0xa6/0x250 fs/io_uring.c:2151
 io_submit_sqe+0x7e5/0x4a5d
 io_submit_sqes+0x278/0x6c0 fs/io_uring.c:7882
 __io_sq_thread fs/io_uring.c:7954 [inline]
 io_sq_thread+0x5fc/0xd90 fs/io_uring.c:8029
 ret_from_fork+0x1f/0x30

read to 0xffff888127e5ba00 of 4 bytes by task 13670 on cpu 1:
 __io_cqring_events fs/io_uring.c:1830 [inline]
 io_cqring_events fs/io_uring.c:2739 [inline]
 io_cqring_wait+0x187/0x11e0 fs/io_uring.c:8256
 __do_sys_io_uring_enter fs/io_uring.c:10950 [inline]
 __se_sys_io_uring_enter+0x70c/0xbe0 fs/io_uring.c:10850
 __x64_sys_io_uring_enter+0x74/0x80 fs/io_uring.c:10850
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x000003f5 -> 0x0000040e

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13670 Comm: syz-executor.1 Not tainted 5.17.0-syzkaller-12882-g1930a6e739c4-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/03/29 11:03 upstream 1930a6e739c4 6bdac766 .config log report info KCSAN: data-race in __io_fill_cqe_req / io_cqring_wait
* Struck through repros no longer work on HEAD.