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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a6bd6c933339 Add linux-next specific files for 20240328
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16b5ffe6180000
kernel config: https://syzkaller.appspot.com/x/.config?x=b0058bda1436e073
dashboard link: https://syzkaller.appspot.com/bug?extid=2cd91b51c468ad5df25b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7c1618ff7d25/disk-a6bd6c93.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/875519f620fe/vmlinux-a6bd6c93.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ad92b057fb96/bzImage-a6bd6c93.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2cd91b...@syzkaller.appspotmail.com

=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
6.9.0-rc1-next-20240328-syzkaller #0 Not tainted
-----------------------------------------------------
syz-executor.0/6478 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire:
ffff88805d4cea18 (&htab->buckets[i].lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff88805d4cea18 (&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:
ffff8880172f0120 ((worker)->lock){-.-.}-{2:2}, at: kthread_queue_work+0x27/0x180 kernel/kthread.c:1019
which would create a new lock dependency:
((worker)->lock){-.-.}-{2:2} -> (&htab->buckets[i].lock){+...}-{2:2}

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

... which became HARDIRQ-irq-safe at:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
kthread_queue_work+0x27/0x180 kernel/kthread.c:1019
pit_timer_fn+0xa5/0x180 arch/x86/kvm/i8254.c:276
__run_hrtimer kernel/time/hrtimer.c:1692 [inline]
__hrtimer_run_queues+0x5a5/0xd50 kernel/time/hrtimer.c:1756
hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
__sysvec_apic_timer_interrupt+0x110/0x3f0 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
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
kvm_vm_ioctl_set_pit+0x83/0x130 arch/x86/kvm/x86.c:6417
kvm_arch_vm_ioctl+0xd4a/0x1710 arch/x86/kvm/x86.c:7153
kvm_vm_ioctl+0x84c/0xd30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:5348
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75

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

... which became HARDIRQ-irq-unsafe at:
...
lock_acquire+0x1ed/0x550 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_update_common+0x20c/0xa30 net/core/sock_map.c:1007
sock_map_update_elem_sys+0x5a4/0x910 net/core/sock_map.c:581
map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641
__sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5619
__do_sys_bpf kernel/bpf/syscall.c:5738 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5736 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75

other info that might help us debug this:

Possible interrupt unsafe locking scenario:

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

*** DEADLOCK ***

3 locks held by syz-executor.0/6478:
#0: ffffffff8e33a0f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#0: ffffffff8e33a0f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x39a/0x820 kernel/rcu/tree_exp.h:939
#1: ffff8880172f0120 ((worker)->lock){-.-.}-{2:2}, at: kthread_queue_work+0x27/0x180 kernel/kthread.c:1019
#2: ffffffff8e334d60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
#2: ffffffff8e334d60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
#2: ffffffff8e334d60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2395 [inline]
#2: ffffffff8e334d60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x1fc/0x530 kernel/trace/bpf_trace.c:2437

the dependencies between HARDIRQ-irq-safe lock and the holding lock:
-> ((worker)->lock){-.-.}-{2:2} {
IN-HARDIRQ-W at:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
kthread_queue_work+0x27/0x180 kernel/kthread.c:1019
pit_timer_fn+0xa5/0x180 arch/x86/kvm/i8254.c:276
__run_hrtimer kernel/time/hrtimer.c:1692 [inline]
__hrtimer_run_queues+0x5a5/0xd50 kernel/time/hrtimer.c:1756
hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
__sysvec_apic_timer_interrupt+0x110/0x3f0 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
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
kvm_vm_ioctl_set_pit+0x83/0x130 arch/x86/kvm/x86.c:6417
kvm_arch_vm_ioctl+0xd4a/0x1710 arch/x86/kvm/x86.c:7153
kvm_vm_ioctl+0x84c/0xd30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:5348
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
IN-SOFTIRQ-W at:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
kthread_queue_work+0x27/0x180 kernel/kthread.c:1019
pit_timer_fn+0xa5/0x180 arch/x86/kvm/i8254.c:276
__run_hrtimer kernel/time/hrtimer.c:1692 [inline]
__hrtimer_run_queues+0x5a5/0xd50 kernel/time/hrtimer.c:1756
hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
__sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1049
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
__debug_check_no_obj_freed lib/debugobjects.c:998 [inline]
debug_check_no_obj_freed+0x561/0x580 lib/debugobjects.c:1019
slab_free_hook mm/slub.c:2152 [inline]
slab_free mm/slub.c:4363 [inline]
kmem_cache_free+0x10f/0x340 mm/slub.c:4438
rcu_do_batch kernel/rcu/tree.c:2196 [inline]
rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471
__do_softirq+0x2c6/0x980 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
__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:203
unwind_next_frame+0x8d6/0x2a00 arch/x86/kernel/unwind_orc.c:517
arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
kasan_kmalloc include/linux/kasan.h:211 [inline]
kmalloc_node_trace_noprof+0x1d3/0x300 mm/slub.c:4091
kmalloc_node_noprof include/linux/slab.h:677 [inline]
__get_vm_area_node+0x11a/0x280 mm/vmalloc.c:3070
__vmalloc_node_range_noprof+0x3df/0x1490 mm/vmalloc.c:3763
__vmalloc_node_noprof mm/vmalloc.c:3868 [inline]
__vmalloc_noprof+0x79/0x90 mm/vmalloc.c:3882
kvm_alloc_memslot_metadata arch/x86/kvm/x86.c:12802 [inline]
kvm_arch_prepare_memory_region+0x2aa/0xdd0 arch/x86/kvm/x86.c:12876
kvm_prepare_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1718 [inline]
kvm_set_memslot+0x588/0x1280 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1948
__kvm_set_memory_region+0x90e/0xaf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2127
kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:2148 [inline]
kvm_vm_ioctl_set_memory_region+0x6d/0xa0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2160
kvm_vm_ioctl+0xa45/0xd30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:5169
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
INITIAL USE at:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170
kthread_worker_fn+0x236/0xaf0 kernel/kthread.c:828
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: [<ffffffff9292d120>] __kthread_create_worker.__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+0x1ed/0x550 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_update_common+0x20c/0xa30 net/core/sock_map.c:1007
sock_map_update_elem_sys+0x5a4/0x910 net/core/sock_map.c:581
map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641
__sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5619
__do_sys_bpf kernel/bpf/syscall.c:5738 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5736 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
INITIAL USE at:
lock_acquire+0x1ed/0x550 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_update_common+0x20c/0xa30 net/core/sock_map.c:1007
sock_map_update_elem_sys+0x5a4/0x910 net/core/sock_map.c:581
map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641
__sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5619
__do_sys_bpf kernel/bpf/syscall.c:5738 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5736 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
}
... key at: [<ffffffff94aee2e0>] sock_hash_alloc.__key+0x0/0x20
... acquired at:
lock_acquire+0x1ed/0x550 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:1233 [inline]
__bpf_prog_run include/linux/filter.h:667 [inline]
bpf_prog_run include/linux/filter.h:674 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2396 [inline]
bpf_trace_run2+0x2ec/0x530 kernel/trace/bpf_trace.c:2437
trace_sched_kthread_work_queue_work include/trace/events/sched.h:64 [inline]
kthread_insert_work+0x419/0x480 kernel/kthread.c:993
kthread_queue_work+0xff/0x180 kernel/kthread.c:1021
synchronize_rcu_expedited_queue_work kernel/rcu/tree_exp.h:469 [inline]
synchronize_rcu_expedited+0x593/0x820 kernel/rcu/tree_exp.h:949
packet_release+0x9ef/0xcc0 net/packet/af_packet.c:3167
__sock_release net/socket.c:659 [inline]
sock_release+0x82/0x150 net/socket.c:687
__sys_socketpair+0x6c9/0x720
__do_sys_socketpair net/socket.c:1822 [inline]
__se_sys_socketpair net/socket.c:1819 [inline]
__x64_sys_socketpair+0x9b/0xb0 net/socket.c:1819
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75


stack backtrace:
CPU: 1 PID: 6478 Comm: syz-executor.0 Not tainted 6.9.0-rc1-next-20240328-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
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+0x1ed/0x550 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:1233 [inline]
__bpf_prog_run include/linux/filter.h:667 [inline]
bpf_prog_run include/linux/filter.h:674 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2396 [inline]
bpf_trace_run2+0x2ec/0x530 kernel/trace/bpf_trace.c:2437
trace_sched_kthread_work_queue_work include/trace/events/sched.h:64 [inline]
kthread_insert_work+0x419/0x480 kernel/kthread.c:993
kthread_queue_work+0xff/0x180 kernel/kthread.c:1021
synchronize_rcu_expedited_queue_work kernel/rcu/tree_exp.h:469 [inline]
synchronize_rcu_expedited+0x593/0x820 kernel/rcu/tree_exp.h:949
packet_release+0x9ef/0xcc0 net/packet/af_packet.c:3167
__sock_release net/socket.c:659 [inline]
sock_release+0x82/0x150 net/socket.c:687
__sys_socketpair+0x6c9/0x720
__do_sys_socketpair net/socket.c:1822 [inline]
__se_sys_socketpair net/socket.c:1819 [inline]
__x64_sys_socketpair+0x9b/0xb0 net/socket.c:1819
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f8906c7dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8907a530c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007f8906dabf80 RCX: 00007f8906c7dda9
RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000011
RBP: 00007f8906cca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020001080 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f8906dabf80 R15: 00007ffd9a605df8
</TASK>
------------[ cut here ]------------
raw_local_irq_restore() called with IRQs enabled
WARNING: CPU: 1 PID: 6478 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x29/0x40 kernel/locking/irqflag-debug.c:10
Modules linked in:
CPU: 1 PID: 6478 Comm: syz-executor.0 Not tainted 6.9.0-rc1-next-20240328-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:warn_bogus_irq_restore+0x29/0x40 kernel/locking/irqflag-debug.c:10
Code: 90 f3 0f 1e fa 90 80 3d f4 fc 13 04 00 74 06 90 c3 cc cc cc cc c6 05 e5 fc 13 04 01 90 48 c7 c7 c0 cd ca 8b e8 68 60 d8 f5 90 <0f> 0b 90 90 90 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f
RSP: 0018:ffffc9000af1f958 EFLAGS: 00010246
RAX: 6b1746de98bfcd00 RBX: 1ffff920015e3f30 RCX: 0000000000040000
RDX: ffffc9000f782000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc9000af1f9f0 R08: ffffffff815802c2 R09: fffffbfff1c39b10
R10: dffffc0000000000 R11: fffffbfff1c39b10 R12: dffffc0000000000
R13: 1ffff920015e3f2c R14: ffffc9000af1f980 R15: 0000000000000246
FS: 00007f8907a536c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001080 CR3: 0000000022368000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
_raw_spin_unlock_irqrestore+0x120/0x140 kernel/locking/spinlock.c:194
kthread_queue_work+0x110/0x180 kernel/kthread.c:1024
synchronize_rcu_expedited_queue_work kernel/rcu/tree_exp.h:469 [inline]
synchronize_rcu_expedited+0x593/0x820 kernel/rcu/tree_exp.h:949
packet_release+0x9ef/0xcc0 net/packet/af_packet.c:3167
__sock_release net/socket.c:659 [inline]
sock_release+0x82/0x150 net/socket.c:687
__sys_socketpair+0x6c9/0x720
__do_sys_socketpair net/socket.c:1822 [inline]
__se_sys_socketpair net/socket.c:1819 [inline]
__x64_sys_socketpair+0x9b/0xb0 net/socket.c:1819
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f8906c7dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8907a530c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007f8906dabf80 RCX: 00007f8906c7dda9
RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000011
RBP: 00007f8906cca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020001080 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f8906dabf80 R15: 00007ffd9a605df8
</TASK>


---
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[Jakub Sitnicki]

#syz fix: bpf, sockmap: Prevent lock inversion deadlock in map delete elem