[syzbot] [bpf?] [net?] possible deadlock in wq_worker_tick

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: ea80e3ed09ab net: ethernet: mtk_eth_soc: fix PPE hanging i..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=13f2ea6e180000
kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440
dashboard link: https://syzkaller.appspot.com/bug?extid=8627369462e8429d7cd6
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15a8fac9180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1619b83a180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4c6c49a7ef5c/disk-ea80e3ed.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/242942b30f2d/vmlinux-ea80e3ed.xz
kernel image: https://storage.googleapis.com/syzbot-assets/74dcc2059655/bzImage-ea80e3ed.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+862736...@syzkaller.appspotmail.com

=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
6.8.0-syzkaller-05221-gea80e3ed09ab #0 Not tainted
-----------------------------------------------------
kworker/0:2/782 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire:
ffff888022c5e820 (&htab->buckets[i].lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888022c5e820 (&htab->buckets[i].lock){+...}-{2:2}, at: sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939

and this task is already holding:
ffff888014ca0018 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x6ec/0xec0
which would create a new lock dependency:
(&pool->lock){-.-.}-{2:2} -> (&htab->buckets[i].lock){+...}-{2:2}

but this new dependency connects a HARDIRQ-irq-safe lock:
(&pool->lock){-.-.}-{2:2}

... which became HARDIRQ-irq-safe at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
wq_worker_tick+0x207/0x440 kernel/workqueue.c:1501
scheduler_tick+0x375/0x6e0 kernel/sched/core.c:5699
update_process_times+0x202/0x230 kernel/time/timer.c:2481
tick_periodic+0x190/0x220 kernel/time/tick-common.c:100
tick_handle_periodic+0x4a/0x160 kernel/time/tick-common.c:112
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
__sysvec_apic_timer_interrupt+0x107/0x3a0 arch/x86/kernel/apic/apic.c:1049
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
__sanitizer_cov_trace_switch+0x6/0x120 kernel/kcov.c:317
unwind_next_frame+0xff6/0x2a00 arch/x86/kernel/unwind_orc.c:581
__unwind_start+0x641/0x7c0 arch/x86/kernel/unwind_orc.c:760
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x103/0x1b0 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
save_stack+0xfb/0x1f0 mm/page_owner.c:129
__set_page_owner+0x29/0x380 mm/page_owner.c:195
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533
prep_new_page mm/page_alloc.c:1540 [inline]
get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311
__alloc_pages+0x256/0x680 mm/page_alloc.c:4569
alloc_pages_mpol+0x3de/0x650 mm/mempolicy.c:2133
__get_free_pages+0xc/0x30 mm/page_alloc.c:4616
kasan_populate_vmalloc_pte+0x38/0xe0 mm/kasan/shadow.c:311
apply_to_pte_range mm/memory.c:2619 [inline]
apply_to_pmd_range mm/memory.c:2663 [inline]
apply_to_pud_range mm/memory.c:2699 [inline]
apply_to_p4d_range mm/memory.c:2735 [inline]
__apply_to_page_range+0x8ec/0xe40 mm/memory.c:2769
pcpu_get_vm_areas+0x3749/0x4fb0 mm/vmalloc.c:4232
pcpu_create_chunk+0x69a/0xbc0 mm/percpu-vm.c:342
pcpu_balance_populated mm/percpu.c:2101 [inline]
pcpu_balance_workfn+0xc4d/0xd40 mm/percpu.c:2238
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

to a HARDIRQ-irq-unsafe lock:
(&htab->buckets[i].lock){+...}-{2:2}

... which became HARDIRQ-irq-unsafe at:
...
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_hash_free+0x164/0x820 net/core/sock_map.c:1154
bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

other info that might help us debug this:

Possible interrupt unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&htab->buckets[i].lock);
local_irq_disable();
lock(&pool->lock);
lock(&htab->buckets[i].lock);
<Interrupt>
lock(&pool->lock);

*** DEADLOCK ***

5 locks held by kworker/0:2/782:
#0: ffff888014c78948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
#0: ffff888014c78948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
#1: ffffc90004097d00 ((work_completion)(&aux->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
#1: ffffc90004097d00 ((work_completion)(&aux->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
#2: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#2: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#2: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __queue_work+0x198/0xec0 kernel/workqueue.c:2324
#3: ffff888014ca0018 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x6ec/0xec0
#4: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#4: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#4: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
#4: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x14a/0x460 kernel/trace/bpf_trace.c:2421

the dependencies between HARDIRQ-irq-safe lock and the holding lock:
-> (&pool->lock){-.-.}-{2:2} {
IN-HARDIRQ-W at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
wq_worker_tick+0x207/0x440 kernel/workqueue.c:1501
scheduler_tick+0x375/0x6e0 kernel/sched/core.c:5699
update_process_times+0x202/0x230 kernel/time/timer.c:2481
tick_periodic+0x190/0x220 kernel/time/tick-common.c:100
tick_handle_periodic+0x4a/0x160 kernel/time/tick-common.c:112
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
__sysvec_apic_timer_interrupt+0x107/0x3a0 arch/x86/kernel/apic/apic.c:1049
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
__sanitizer_cov_trace_switch+0x6/0x120 kernel/kcov.c:317
unwind_next_frame+0xff6/0x2a00 arch/x86/kernel/unwind_orc.c:581
__unwind_start+0x641/0x7c0 arch/x86/kernel/unwind_orc.c:760
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x103/0x1b0 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
save_stack+0xfb/0x1f0 mm/page_owner.c:129
__set_page_owner+0x29/0x380 mm/page_owner.c:195
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533
prep_new_page mm/page_alloc.c:1540 [inline]
get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311
__alloc_pages+0x256/0x680 mm/page_alloc.c:4569
alloc_pages_mpol+0x3de/0x650 mm/mempolicy.c:2133
__get_free_pages+0xc/0x30 mm/page_alloc.c:4616
kasan_populate_vmalloc_pte+0x38/0xe0 mm/kasan/shadow.c:311
apply_to_pte_range mm/memory.c:2619 [inline]
apply_to_pmd_range mm/memory.c:2663 [inline]
apply_to_pud_range mm/memory.c:2699 [inline]
apply_to_p4d_range mm/memory.c:2735 [inline]
__apply_to_page_range+0x8ec/0xe40 mm/memory.c:2769
pcpu_get_vm_areas+0x3749/0x4fb0 mm/vmalloc.c:4232
pcpu_create_chunk+0x69a/0xbc0 mm/percpu-vm.c:342
pcpu_balance_populated mm/percpu.c:2101 [inline]
pcpu_balance_workfn+0xc4d/0xd40 mm/percpu.c:2238
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
IN-SOFTIRQ-W at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
__queue_work+0x6ec/0xec0
call_timer_fn+0x17e/0x600 kernel/time/timer.c:1792
expire_timers kernel/time/timer.c:1838 [inline]
__run_timers kernel/time/timer.c:2408 [inline]
__run_timer_base+0x695/0x8e0 kernel/time/timer.c:2419
run_timer_base kernel/time/timer.c:2428 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2438
__do_softirq+0x2bc/0x943 kernel/softirq.c:554
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633
irq_exit_rcu+0x9/0x30 kernel/softirq.c:645
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:742
default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x22f/0x5d0 kernel/sched/idle.c:332
cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:430
rest_init+0x2e0/0x300 init/main.c:730
arch_call_rest_init+0xe/0x10 init/main.c:831
start_kernel+0x47a/0x500 init/main.c:1077
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:509
x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:490
common_startup_64+0x13e/0x147
INITIAL USE at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
__queue_work+0x6ec/0xec0
queue_work_on+0x14f/0x250 kernel/workqueue.c:2435
queue_work include/linux/workqueue.h:605 [inline]
start_poll_synchronize_rcu_expedited+0xf7/0x150 kernel/rcu/tree_exp.h:1017
rcu_init+0xea/0x140 kernel/rcu/tree.c:5240
start_kernel+0x1f7/0x500 init/main.c:969
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:509
x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:490
common_startup_64+0x13e/0x147
}
... key at: [<ffffffff926c0e60>] init_worker_pool.__key+0x0/0x20

the dependencies between the lock to be acquired
and HARDIRQ-irq-unsafe lock:
-> (&htab->buckets[i].lock){+...}-{2:2} {
HARDIRQ-ON-W at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_hash_free+0x164/0x820 net/core/sock_map.c:1154
bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
INITIAL USE at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_hash_free+0x164/0x820 net/core/sock_map.c:1154
bpf_map_free_deferred+0xe6/0x110 kernel/bpf/syscall.c:734
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
}
... key at: [<ffffffff94882300>] sock_hash_alloc.__key+0x0/0x20
... acquired at:
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939
bpf_prog_2c29ac5cdc6b1842+0x42/0x46
bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
__bpf_prog_run include/linux/filter.h:657 [inline]
bpf_prog_run include/linux/filter.h:664 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
bpf_trace_run3+0x238/0x460 kernel/trace/bpf_trace.c:2421
trace_workqueue_queue_work include/trace/events/workqueue.h:23 [inline]
__queue_work+0xe5b/0xec0 kernel/workqueue.c:2382
queue_work_on+0x14f/0x250 kernel/workqueue.c:2435
__bpf_free_used_maps kernel/bpf/core.c:2716 [inline]
bpf_free_used_maps kernel/bpf/core.c:2722 [inline]
bpf_prog_free_deferred+0x21d/0x710 kernel/bpf/core.c:2761
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243


stack backtrace:
CPU: 0 PID: 782 Comm: kworker/0:2 Not tainted 6.8.0-syzkaller-05221-gea80e3ed09ab #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: events bpf_prog_free_deferred
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
print_bad_irq_dependency kernel/locking/lockdep.c:2626 [inline]
check_irq_usage kernel/locking/lockdep.c:2865 [inline]
check_prev_add kernel/locking/lockdep.c:3138 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain+0x4dc7/0x58e0 kernel/locking/lockdep.c:3869
__lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939
bpf_prog_2c29ac5cdc6b1842+0x42/0x46
bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
__bpf_prog_run include/linux/filter.h:657 [inline]
bpf_prog_run include/linux/filter.h:664 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
bpf_trace_run3+0x238/0x460 kernel/trace/bpf_trace.c:2421
trace_workqueue_queue_work include/trace/events/workqueue.h:23 [inline]
__queue_work+0xe5b/0xec0 kernel/workqueue.c:2382
queue_work_on+0x14f/0x250 kernel/workqueue.c:2435
__bpf_free_used_maps kernel/bpf/core.c:2716 [inline]
bpf_free_used_maps kernel/bpf/core.c:2722 [inline]
bpf_prog_free_deferred+0x21d/0x710 kernel/bpf/core.c:2761
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
</TASK>


---
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[Hillf Danton]

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git ea80e3ed09ab

--- x/net/core/sock_map.c
+++ y/net/core/sock_map.c
@@ -932,11 +932,12 @@ static long sock_hash_delete_elem(struct
struct bpf_shtab_bucket *bucket;
struct bpf_shtab_elem *elem;
int ret = -ENOENT;
+ unsigned long flags;

hash = sock_hash_bucket_hash(key, key_size);
bucket = sock_hash_select_bucket(htab, hash);

- spin_lock_bh(&bucket->lock);
+ spin_lock_irqsave(&bucket->lock, flags);
elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
if (elem) {
hlist_del_rcu(&elem->node);
@@ -944,7 +945,7 @@ static long sock_hash_delete_elem(struct
sock_hash_free_elem(htab, elem);
ret = 0;
}
- spin_unlock_bh(&bucket->lock);
+ spin_unlock_irqrestore(&bucket->lock, flags);
return ret;
}

@@ -1143,6 +1144,8 @@ static void sock_hash_free(struct bpf_ma
*/
synchronize_rcu();
for (i = 0; i < htab->buckets_num; i++) {
+ unsigned long flags;
+
bucket = sock_hash_select_bucket(htab, i);

/* We are racing with sock_hash_delete_from_link to
@@ -1151,11 +1154,11 @@ static void sock_hash_free(struct bpf_ma
* exists, psock exists and holds a ref to socket. That
* lets us to grab a socket ref too.
*/
- spin_lock_bh(&bucket->lock);
+ spin_lock_irqsave(&bucket->lock, flags);
hlist_for_each_entry(elem, &bucket->head, node)
sock_hold(elem->sk);
hlist_move_list(&bucket->head, &unlink_list);
- spin_unlock_bh(&bucket->lock);
+ spin_unlock_irqrestore(&bucket->lock, flags);

/* Process removed entries out of atomic context to
* block for socket lock before deleting the psock's
--

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+862736...@syzkaller.appspotmail.com

Tested on:

commit: ea80e3ed net: ethernet: mtk_eth_soc: fix PPE hanging i..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git
console output: https://syzkaller.appspot.com/x/log.txt?x=12324231180000

kernel config: https://syzkaller.appspot.com/x/.config?x=6fb1be60a193d440
dashboard link: https://syzkaller.appspot.com/bug?extid=8627369462e8429d7cd6
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=15812546180000

Note: testing is done by a robot and is best-effort only.

[Jakub Sitnicki]

#syz dup: [syzbot] [bpf?] [net?] possible deadlock in ahci_single_level_irq_intr