[moderation/CI] Re: io_uring: avoid uring_lock for IORING_SETUP_SINGLE_ISSUER

[syzbot ci]

syzbot ci has tested the following series

[v5] io_uring: avoid uring_lock for IORING_SETUP_SINGLE_ISSUER
https://lore.kernel.org/all/20251215200909.3...@purestorage.com
* [PATCH v5 1/6] io_uring: use release-acquire ordering for IORING_SETUP_R_DISABLED
* [PATCH v5 2/6] io_uring: clear IORING_SETUP_SINGLE_ISSUER for IORING_SETUP_SQPOLL
* [PATCH v5 3/6] io_uring: ensure io_uring_create() initializes submitter_task
* [PATCH v5 4/6] io_uring: use io_ring_submit_lock() in io_iopoll_req_issued()
* [PATCH v5 5/6] io_uring: factor out uring_lock helpers
* [PATCH v5 6/6] io_uring: avoid uring_lock for IORING_SETUP_SINGLE_ISSUER

and found the following issue:
KASAN: slab-use-after-free Read in task_work_add

Full report is available here:
https://ci.syzbot.org/series/bce89909-ebf2-45f6-be49-bbd46e33e966

***

KASAN: slab-use-after-free Read in task_work_add

tree: torvalds
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base: d358e5254674b70f34c847715ca509e46eb81e6f
arch: amd64
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
config: https://ci.syzbot.org/builds/db5ac991-f49c-460f-80e4-2a33be76fe7c/config
syz repro: https://ci.syzbot.org/findings/ddbf1feb-6618-4c0f-9a16-15b856f20d71/syz_repro

==================================================================
BUG: KASAN: slab-use-after-free in task_work_add+0xd7/0x440 kernel/task_work.c:73
Read of size 8 at addr ffff88816a8826f8 by task kworker/u9:2/54

CPU: 0 UID: 0 PID: 54 Comm: kworker/u9:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: iou_exit io_ring_exit_work
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x240 mm/kasan/report.c:482
kasan_report+0x118/0x150 mm/kasan/report.c:595
task_work_add+0xd7/0x440 kernel/task_work.c:73
io_ring_ctx_lock_nested io_uring/io_uring.h:271 [inline]
io_ring_ctx_lock io_uring/io_uring.h:282 [inline]
io_req_caches_free+0x342/0x3e0 io_uring/io_uring.c:2869
io_ring_ctx_free+0x56a/0x8e0 io_uring/io_uring.c:2908
io_ring_exit_work+0xff9/0x1220 io_uring/io_uring.c:3113
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>

Allocated by task 7671:
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:339 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_node_noprof+0x43c/0x720 mm/slub.c:5315
alloc_task_struct_node kernel/fork.c:184 [inline]
dup_task_struct+0x57/0x9a0 kernel/fork.c:915
copy_process+0x4ea/0x3950 kernel/fork.c:2052
kernel_clone+0x21e/0x820 kernel/fork.c:2651
__do_sys_clone3 kernel/fork.c:2953 [inline]
__se_sys_clone3+0x256/0x2d0 kernel/fork.c:2932
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6024:
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6668 [inline]
kmem_cache_free+0x197/0x620 mm/slub.c:6779
rcu_do_batch kernel/rcu/tree.c:2605 [inline]
rcu_core+0xd70/0x1870 kernel/rcu/tree.c:2857
handle_softirqs+0x27d/0x850 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline]
sysvec_call_function_single+0xa3/0xc0 arch/x86/kernel/smp.c:266
asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:704

Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3119 [inline]
call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3239
rcu_do_batch kernel/rcu/tree.c:2605 [inline]
rcu_core+0xd70/0x1870 kernel/rcu/tree.c:2857
handle_softirqs+0x27d/0x850 kernel/softirq.c:622
run_ksoftirqd+0x9b/0x100 kernel/softirq.c:1063
smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Second to last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3119 [inline]
call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3239
context_switch kernel/sched/core.c:5259 [inline]
__schedule+0x14c4/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

The buggy address belongs to the object at ffff88816a881d40
which belongs to the cache task_struct of size 7232
The buggy address is located 2488 bytes inside of
freed 7232-byte region [ffff88816a881d40, ffff88816a883980)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16a880
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8881726b0441
anon flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88816040a500 0000000000000000 0000000000000001
raw: 0000000000000000 0000000080040004 00000000f5000000 ffff8881726b0441
head: 057ff00000000040 ffff88816040a500 0000000000000000 0000000000000001
head: 0000000000000000 0000000080040004 00000000f5000000 ffff8881726b0441
head: 057ff00000000003 ffffea0005aa2001 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7291, tgid 7291 (syz.2.649), ts 88142964676, free_ts 88127352940
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
prep_new_page mm/page_alloc.c:1854 [inline]
get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
alloc_slab_page mm/slub.c:3075 [inline]
allocate_slab+0x86/0x3b0 mm/slub.c:3248
new_slab mm/slub.c:3302 [inline]
___slab_alloc+0xf2b/0x1960 mm/slub.c:4656
__slab_alloc+0x65/0x100 mm/slub.c:4779
__slab_alloc_node mm/slub.c:4855 [inline]
slab_alloc_node mm/slub.c:5251 [inline]
kmem_cache_alloc_node_noprof+0x4ce/0x720 mm/slub.c:5315
alloc_task_struct_node kernel/fork.c:184 [inline]
dup_task_struct+0x57/0x9a0 kernel/fork.c:915
copy_process+0x4ea/0x3950 kernel/fork.c:2052
kernel_clone+0x21e/0x820 kernel/fork.c:2651
__do_sys_clone3 kernel/fork.c:2953 [inline]
__se_sys_clone3+0x256/0x2d0 kernel/fork.c:2932
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5275 tgid 5275 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
__slab_free+0x21b/0x2a0 mm/slub.c:6004
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
getname_flags+0xb8/0x540 fs/namei.c:146
getname include/linux/fs.h:2498 [inline]
do_sys_openat2+0xbc/0x200 fs/open.c:1426
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
ffff88816a882580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88816a882600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88816a882680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88816a882700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88816a882780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syz...@syzkaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzk...@googlegroups.com.

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[Aleksandr Nogikh]

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[syzbot ci]

syzbot ci has tested the following series

[v6] io_uring: avoid uring_lock for IORING_SETUP_SINGLE_ISSUER
https://lore.kernel.org/all/20251218024459.1...@purestorage.com
* [PATCH v6 1/6] io_uring: use release-acquire ordering for IORING_SETUP_R_DISABLED
* [PATCH v6 2/6] io_uring: clear IORING_SETUP_SINGLE_ISSUER for IORING_SETUP_SQPOLL
* [PATCH v6 3/6] io_uring: ensure submitter_task is valid for io_ring_ctx's lifetime
* [PATCH v6 4/6] io_uring: use io_ring_submit_lock() in io_iopoll_req_issued()
* [PATCH v6 5/6] io_uring: factor out uring_lock helpers
* [PATCH v6 6/6] io_uring: avoid uring_lock for IORING_SETUP_SINGLE_ISSUER

and found the following issue:

INFO: task hung in io_wq_put_and_exit

Full report is available here:

https://ci.syzbot.org/series/21eac721-670b-4f34-9696-66f9b28233ac

***

INFO: task hung in io_wq_put_and_exit

tree: torvalds
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base: d358e5254674b70f34c847715ca509e46eb81e6f
arch: amd64
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

config: https://ci.syzbot.org/builds/1710cffe-7d78-4489-9aa1-823b8c2532ed/config
syz repro: https://ci.syzbot.org/findings/74ae8703-9484-4d82-aa78-84cc37dcb1ef/syz_repro

INFO: task syz.1.18:6046 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.18 state:D stack:25672 pid:6046 tgid:6045 ppid:5971 task_flags:0x400548 flags:0x00080004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
io_wq_exit_workers io_uring/io-wq.c:1328 [inline]
io_wq_put_and_exit+0x316/0x650 io_uring/io-wq.c:1356
io_uring_clean_tctx+0x11f/0x1a0 io_uring/tctx.c:207
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/cancel.c:652
io_uring_files_cancel include/linux/io_uring.h:19 [inline]
do_exit+0x345/0x2310 kernel/exit.c:911
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6a8b58f7c9
RSP: 002b:00007f6a8c4a00e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f6a8b7e5fa8 RCX: 00007f6a8b58f7c9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f6a8b7e5fac
RBP: 00007f6a8b7e5fa0 R08: 3fffffffffffffff R09: 0000000000000000
R10: 0000000000000800 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6a8b7e6038 R14: 00007ffcac96d220 R15: 00007ffcac96d308
</TASK>
INFO: task iou-wrk-6046:6047 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:iou-wrk-6046 state:D stack:27760 pid:6047 tgid:6045 ppid:5971 task_flags:0x404050 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
io_ring_ctx_lock_nested+0x2b3/0x380 io_uring/io_uring.h:283
io_ring_ctx_lock io_uring/io_uring.h:290 [inline]
io_ring_submit_lock io_uring/io_uring.h:554 [inline]
io_files_update+0x677/0x7f0 io_uring/rsrc.c:504
__io_issue_sqe+0x181/0x4b0 io_uring/io_uring.c:1818
io_issue_sqe+0x1de/0x1190 io_uring/io_uring.c:1841
io_wq_submit_work+0x6e9/0xb90 io_uring/io_uring.c:1953
io_worker_handle_work+0x7cd/0x1180 io_uring/io-wq.c:650
io_wq_worker+0x42f/0xeb0 io_uring/io-wq.c:704

ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>

INFO: task syz.0.17:6049 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:25592 pid:6049 tgid:6048 ppid:5967 task_flags:0x400548 flags:0x00080004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
io_wq_exit_workers io_uring/io-wq.c:1328 [inline]
io_wq_put_and_exit+0x316/0x650 io_uring/io-wq.c:1356
io_uring_clean_tctx+0x11f/0x1a0 io_uring/tctx.c:207
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/cancel.c:652
io_uring_files_cancel include/linux/io_uring.h:19 [inline]
do_exit+0x345/0x2310 kernel/exit.c:911
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa96a98f7c9
RSP: 002b:00007fa96b7430e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007fa96abe5fa8 RCX: 00007fa96a98f7c9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fa96abe5fac
RBP: 00007fa96abe5fa0 R08: 3fffffffffffffff R09: 0000000000000000
R10: 0000000000000800 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa96abe6038 R14: 00007ffd9fcc00d0 R15: 00007ffd9fcc01b8
</TASK>
INFO: task iou-wrk-6049:6050 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:iou-wrk-6049 state:D stack:27760 pid:6050 tgid:6048 ppid:5967 task_flags:0x404050 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
io_ring_ctx_lock_nested+0x2b3/0x380 io_uring/io_uring.h:283
io_ring_ctx_lock io_uring/io_uring.h:290 [inline]
io_ring_submit_lock io_uring/io_uring.h:554 [inline]
io_files_update+0x677/0x7f0 io_uring/rsrc.c:504
__io_issue_sqe+0x181/0x4b0 io_uring/io_uring.c:1818
io_issue_sqe+0x1de/0x1190 io_uring/io_uring.c:1841
io_wq_submit_work+0x6e9/0xb90 io_uring/io_uring.c:1953
io_worker_handle_work+0x7cd/0x1180 io_uring/io-wq.c:650
io_wq_worker+0x42f/0xeb0 io_uring/io-wq.c:704

ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>

INFO: task syz.2.19:6052 blocked for more than 144 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.19 state:D stack:26208 pid:6052 tgid:6051 ppid:5972 task_flags:0x400548 flags:0x00080004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
io_wq_exit_workers io_uring/io-wq.c:1328 [inline]
io_wq_put_and_exit+0x316/0x650 io_uring/io-wq.c:1356
io_uring_clean_tctx+0x11f/0x1a0 io_uring/tctx.c:207
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/cancel.c:652
io_uring_files_cancel include/linux/io_uring.h:19 [inline]
do_exit+0x345/0x2310 kernel/exit.c:911
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b5cb8f7c9
RSP: 002b:00007f4b5d9a80e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f4b5cde5fa8 RCX: 00007f4b5cb8f7c9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f4b5cde5fac
RBP: 00007f4b5cde5fa0 R08: 3fffffffffffffff R09: 0000000000000000
R10: 0000000000000800 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4b5cde6038 R14: 00007ffcdd64aed0 R15: 00007ffcdd64afb8
</TASK>
INFO: task iou-wrk-6052:6053 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:iou-wrk-6052 state:D stack:27760 pid:6053 tgid:6051 ppid:5972 task_flags:0x404050 flags:0x00080006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
io_ring_ctx_lock_nested+0x2b3/0x380 io_uring/io_uring.h:283
io_ring_ctx_lock io_uring/io_uring.h:290 [inline]
io_ring_submit_lock io_uring/io_uring.h:554 [inline]
io_files_update+0x677/0x7f0 io_uring/rsrc.c:504
__io_issue_sqe+0x181/0x4b0 io_uring/io_uring.c:1818
io_issue_sqe+0x1de/0x1190 io_uring/io_uring.c:1841
io_wq_submit_work+0x6e9/0xb90 io_uring/io_uring.c:1953
io_worker_handle_work+0x7cd/0x1180 io_uring/io-wq.c:650
io_wq_worker+0x42f/0xeb0 io_uring/io-wq.c:704

ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
#0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u10:8/1120:
#0: ffff88823c63a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
#1: ffff88823c624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffff88810ac50788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6363 [inline]
#2: ffff88810ac50788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xb4/0x450 net/wireless/core.c:424
#3: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#3: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#3: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: ieee80211_sta_active_ibss+0xc3/0x330 net/mac80211/ibss.c:635
#4: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#4: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#4: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
#4: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x2390 arch/x86/kernel/unwind_orc.c:479
2 locks held by getty/5656:
#0: ffff8881133040a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900035732f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:9/6480:
#0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888100075948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000546fb80 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000546fb80 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8f30ffc8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by syz-executor/6649:
#0: ffffffff8f30ffc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f30ffc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f30ffc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
2 locks held by syz-executor/6651:
#0: ffffffff8f30ffc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f30ffc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f30ffc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
#1: ffff88823c63a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
4 locks held by syz-executor/6653:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014

Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120

nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf95/0xfe0 kernel/hung_task.c:515

kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>

Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6653 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014

RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: 3f a6 fc 44 89 f9 d3 e5 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ec 91 0c fd 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc90008156590 EFLAGS: 00000002
RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020
RBP: 00000000000003f8 R08: ffff888102f08237 R09: 1ffff110205e1046
R10: dffffc0000000000 R11: ffffffff851b9060 R12: dffffc0000000000
R13: ffffffff998dd9e1 R14: ffffffff99bf2420 R15: 0000000000000000
FS: 0000555595186500(0000) GS:ffff8882a9e37000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055599f9c9018 CR3: 0000000112ed8000 CR4: 00000000000006f0
Call Trace:
<TASK>
serial_port_out include/linux/serial_core.h:811 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x1410/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3129 [inline]
console_flush_one_record kernel/printk/printk.c:3215 [inline]
console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289
__console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426
_printk+0xcf/0x120 kernel/printk/printk.c:2451
br_set_state+0x475/0x710 net/bridge/br_stp.c:57
br_init_port+0x99/0x200 net/bridge/br_stp_if.c:39
new_nbp+0x2f9/0x440 net/bridge/br_if.c:443
br_add_if+0x283/0xeb0 net/bridge/br_if.c:586
do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2963
do_setlink+0xcf0/0x41c0 net/core/rtnetlink.c:3165
rtnl_changelink net/core/rtnetlink.c:3776 [inline]
__rtnl_newlink net/core/rtnetlink.c:3935 [inline]
rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072
rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
__sys_sendto+0x3bd/0x520 net/socket.c:2206
__do_sys_sendto net/socket.c:2213 [inline]
__se_sys_sendto net/socket.c:2209 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2209

do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

RIP: 0033:0x7f780c39165c
Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b
RSP: 002b:00007ffcecb618b0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f780d114620 RCX: 00007f780c39165c
RDX: 0000000000000028 RSI: 00007f780d114670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffcecb61904 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f780d114670 R15: 0000000000000000
</TASK>

[Aleksandr Nogikh]

#syz upstream

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