syzbot

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision	Error
c8ba0b7f-ba8a-4fe6-9b39-d77202076aa7	assessment-kcsan		💥	KCSAN: data-race in io_submit_sqes / io_uring_poll (9)	2026/02/09 11:01	2026/02/09 11:01	2026/02/09 11:01	97745f52f5b9361548048f53f0b3b51b9313fedf	fork/exec ./syz-agent: no such file or directory

==================================================================
BUG: KCSAN: data-race in io_submit_sqes / io_uring_poll

write to 0xffff88811b0b0804 of 2 bytes by task 3493 on cpu 0:
 io_init_req io_uring/io_uring.c:2177 [inline]
 io_submit_sqe io_uring/io_uring.c:2282 [inline]
 io_submit_sqes+0xc11/0x11b0 io_uring/io_uring.c:2435
 __do_sys_io_uring_enter io_uring/io_uring.c:3285 [inline]
 __se_sys_io_uring_enter+0x1bf/0x1c70 io_uring/io_uring.c:3224
 __x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3224
 x64_sys_call+0x27e4/0x3000 arch/x86/include/generated/asm/syscalls_64.h:427
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811b0b0804 of 2 bytes by task 3489 on cpu 1:
 io_uring_poll+0x2f/0x1b0 io_uring/io_uring.c:2930
 vfs_poll include/linux/poll.h:82 [inline]
 __io_arm_poll_handler+0x1ee/0xb80 io_uring/poll.c:581
 io_poll_add+0x69/0xf0 io_uring/poll.c:899
 __io_issue_sqe+0xfd/0x2d0 io_uring/io_uring.c:1793
 io_issue_sqe+0x20b/0xc20 io_uring/io_uring.c:1816
 io_queue_sqe io_uring/io_uring.c:2043 [inline]
 io_submit_sqe io_uring/io_uring.c:2321 [inline]
 io_submit_sqes+0x78a/0x11b0 io_uring/io_uring.c:2435
 __do_sys_io_uring_enter io_uring/io_uring.c:3285 [inline]
 __se_sys_io_uring_enter+0x1bf/0x1c70 io_uring/io_uring.c:3224
 __x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3224
 x64_sys_call+0x27e4/0x3000 arch/x86/include/generated/asm/syscalls_64.h:427
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0100 -> 0x0304

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3489 Comm: syz.2.3 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
==================================================================

Seq	Timestamp	Type	Name	Duration
0/0	2026/02/09 11:01	flow	assessment-kcsan	0m Error: fork/exec ./syz-agent: no such file or directory
1/1	2026/02/09 11:01	action	kernel-checkouter	0m Results: map[KernelSrc:/usr/local/google/home/dvyukov/syzkaller/agent/workdir/cache/src/aaf038e744b3e042036601088a5309ed2ffaacb1]
2/1	2026/02/09 11:01	action	kernel-builder	0m Results: map[KernelObj:/usr/local/google/home/dvyukov/syzkaller/agent/workdir/cache/build/895fe9a4eeab361f680f3b7af14fffdb3a031b9a]
3/1	2026/02/09 11:01	action	codesearch-prepare	0m Error: fork/exec ./syz-agent: no such file or directory Results: map[Index:codesearch-index]