syzbot


KCSAN: data-race in io_req_defer_failed / io_wq_free_work (2)

Status: moderation: reported on 2024/08/11 22:49
Subsystems: io-uring
[Documentation on labels]
Reported-by: syzbot+dba7faa79d195e89e311@syzkaller.appspotmail.com
First crash: 31d, last: 19d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in io_req_defer_failed / io_wq_free_work io-uring 3 102d 129d 0/27 auto-obsoleted due to no activity on 2024/07/07 04:35

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

write to 0xffff8881152cdf48 of 8 bytes by task 4229 on cpu 0:
 io_req_defer_failed+0x6e/0x280 io_uring/io_uring.c:906
 io_req_task_cancel+0x21/0x30 io_uring/io_uring.c:1332
 io_handle_tw_list+0x1b9/0x200 io_uring/io_uring.c:1034
 tctx_task_work_run+0x6c/0x1b0 io_uring/io_uring.c:1106
 tctx_task_work+0x40/0x80 io_uring/io_uring.c:1124
 task_work_run+0x13a/0x1a0 kernel/task_work.c:228
 get_signal+0xeee/0x1080 kernel/signal.c:2689
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881152cdf48 of 8 bytes by task 4230 on cpu 1:
 req_ref_put_and_test io_uring/refs.h:22 [inline]
 io_wq_free_work+0x21/0x160 io_uring/io_uring.c:1750
 io_worker_handle_work+0x4cb/0x9d0 io_uring/io-wq.c:603
 io_wq_worker+0x286/0x820 io_uring/io-wq.c:654
 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: 0x0000000080ac4250 -> 0x0000000080ec4310

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 4230 Comm: iou-wrk-4229 Not tainted 6.11.0-rc4-syzkaller-00143-g3d5f968a177d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/23 22:31 upstream 3d5f968a177d d7d32352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in io_req_defer_failed / io_wq_free_work
2024/08/23 22:31 upstream 3d5f968a177d d7d32352 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in io_req_defer_failed / io_wq_free_work
2024/08/17 01:09 upstream 85652baa895b dbc93b08 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in io_req_defer_failed / io_wq_free_work
2024/08/13 10:45 upstream d74da846046a 7b0f4b46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in io_req_defer_failed / io_wq_free_work
2024/08/11 22:49 upstream 7006fe2f7f78 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in io_req_defer_failed / io_wq_free_work
2024/08/11 22:48 upstream 7006fe2f7f78 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in io_req_defer_failed / io_wq_free_work
* Struck through repros no longer work on HEAD.