syzbot


KCSAN: data-race in io_recv / io_wq_free_work

Status: upstream: reported on 2024/12/13 11:11
Subsystems: io-uring
[Documentation on labels]
Reported-by: syzbot+a697a4754324488bacd7@syzkaller.appspotmail.com
First crash: 8d17h, last: 8d10h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [io-uring?] KCSAN: data-race in io_recv / io_wq_free_work 1 (2) 2024/12/13 14:18

Sample crash report:
==================================================================
BUG: KCSAN: data-race in io_recv / io_wq_free_work

write to 0xffff88814248b848 of 8 bytes by task 22395 on cpu 1:
 io_recv+0x661/0xa70
 io_issue_sqe+0x150/0xc10 io_uring/io_uring.c:1736
 io_poll_issue+0x1a/0x20 io_uring/io_uring.c:1767
 io_poll_check_events io_uring/poll.c:289 [inline]
 io_poll_task_func+0x205/0x7c0 io_uring/poll.c:316
 io_handle_tw_list+0xe3/0x200 io_uring/io_uring.c:1053
 tctx_task_work_run+0x6e/0x1c0 io_uring/io_uring.c:1117
 tctx_task_work+0x40/0x80 io_uring/io_uring.c:1135
 task_work_run+0x13a/0x1a0 kernel/task_work.c:239
 io_run_task_work+0x1b1/0x200 io_uring/io_uring.h:343
 io_cqring_wait io_uring/io_uring.c:2594 [inline]
 __do_sys_io_uring_enter io_uring/io_uring.c:3434 [inline]
 __se_sys_io_uring_enter+0x14f5/0x1ba0 io_uring/io_uring.c:3325
 __x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:3325
 x64_sys_call+0xb5e/0x2dc0 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 0xffff88814248b848 of 8 bytes by task 22396 on cpu 0:
 req_ref_put_and_test io_uring/refs.h:22 [inline]
 io_wq_free_work+0x24/0x1b0 io_uring/io_uring.c:1776
 io_worker_handle_work+0x4cb/0x9d0 io_uring/io-wq.c:604
 io_wq_worker+0x286/0x820 io_uring/io-wq.c:655
 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: 0x0000000085584038 -> 0x0000000085184138

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 22396 Comm: iou-wrk-22395 Not tainted 6.13.0-rc2-syzkaller-00130-g150b567e0d57 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/13 03:40 upstream 150b567e0d57 530e80f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in io_recv / io_wq_free_work
2024/12/12 19:53 upstream 231825b2e1ff 530e80f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in io_recv / io_wq_free_work
* Struck through repros no longer work on HEAD.