[v6.1] INFO: rcu detected stall in nsim_dev_trap_report_work (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fdb6fcb41cc7 Linux 6.1.176
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14e9e566580000
kernel config: https://syzkaller.appspot.com/x/.config?x=acfbe65fbce84c0c
dashboard link: https://syzkaller.appspot.com/bug?extid=f67aec3f4a68b2cc36ef
compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8a12ae1ddcea/disk-fdb6fcb4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d0dd1b27df77/vmlinux-fdb6fcb4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/871bf60ea1f2/bzImage-fdb6fcb4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f67aec...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2687 jiffies s: 66133 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 18025 Comm: kworker/u4:16 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__kasan_check_read+0x0/0x10 mm/kasan/shadow.c:31
Code: 41 5c 41 5d 41 5e 41 5f 5d c3 48 c7 c7 ea ce 60 8c eb 0a 48 c7 c7 01 76 45 8c 48 89 de e8 98 5b 4c 08 31 ed eb d7 00 00 cc cc <89> f6 48 8b 0c 24 31 d2 e9 c3 ec ff ff 0f 1f 00 89 f6 48 8b 0c 24
RSP: 0018:ffffc900001e01f8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000005 RCX: ffffffff81640229
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90af2240
RBP: ffffc900001e0430 R08: dffffc0000000000 R09: 1ffffffff215e44b
R10: dffffc0000000000 R11: fffffbfff215e44c R12: ffff8880252029c8
R13: ffff888025201e02 R14: 000000000000002c R15: ffff8880252029c8
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa13d217dac CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
instrument_atomic_read include/linux/instrumented.h:72 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
hlock_class kernel/locking/lockdep.c:228 [inline]
check_wait_context kernel/locking/lockdep.c:4748 [inline]
__lock_acquire+0x929/0x7bd0 kernel/locking/lockdep.c:4999
lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
trace_call_bpf+0xe0/0x6b0 kernel/trace/bpf_trace.c:134
perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027
perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14
trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40
trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 e2 82 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900001e08a0 EFLAGS: 00000206
RAX: ad5d0f6bbe1d9900 RBX: 1ffff9200003c11c RCX: ad5d0f6bbe1d9900
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adee1a0
RBP: ffffc900001e0988 R08: ffffffff90af232f R09: 1ffffffff215e465
R10: dffffc0000000000 R11: fffffbfff215e466 R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3bb00 R15: 0000000000000002
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock include/linux/rcupdate.h:823 [inline]
percpu_ref_put_many include/linux/percpu-refcount.h:337 [inline]
percpu_ref_put+0xef/0x180 include/linux/percpu-refcount.h:351
obj_cgroup_put include/linux/memcontrol.h:795 [inline]
refill_obj_stock+0x402/0x6a0 mm/memcontrol.c:3347
memcg_slab_free_hook+0x123/0x200 mm/slab.h:569
slab_free mm/slub.c:3682 [inline]
kmem_cache_free+0xe0/0x2a0 mm/slub.c:3709
rcu_do_batch kernel/rcu/tree.c:2297 [inline]
rcu_core+0x9a3/0x1740 kernel/rcu/tree.c:2557
handle_softirqs+0x291/0x910 kernel/softirq.c:596
__do_softirq kernel/softirq.c:630 [inline]
invoke_softirq kernel/softirq.c:470 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> ef cb 23 f7 65 8b 05 f0 7c cd 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000e4978c0 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: ad5d0f6bbe1d9900
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: 0000000000000001
RBP: ffffc9000e497958 R08: ffffffff90af232f R09: 1ffffffff215e465
R10: dffffc0000000000 R11: fffffbfff215e466 R12: dffffc0000000000
R13: ffffea0001548000 R14: ffff8880174409c0 R15: 1ffff92001c92f18
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
get_partial_node+0x469/0x480 mm/slub.c:2252
get_partial mm/slub.c:2330 [inline]
___slab_alloc+0x96d/0x1240 mm/slub.c:3131
__slab_alloc mm/slub.c:3240 [inline]
slab_alloc_node mm/slub.c:3325 [inline]
__kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398
__do_kmalloc_node mm/slab_common.c:935 [inline]
__kmalloc_node_track_caller+0xa0/0x240 mm/slab_common.c:956
kmalloc_reserve net/core/skbuff.c:446 [inline]
__alloc_skb+0x226/0x7d0 net/core/skbuff.c:515
alloc_skb include/linux/skbuff.h:1303 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
nsim_dev_trap_report_work+0x24f/0xa80 drivers/net/netdevsim/dev.c:851
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>


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