[v5.15] BUG: soft lockup in process_srcu

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 16fdf2c7111b Linux 5.15.181
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=140618d4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=78ce1ad3d91bc375
dashboard link: https://syzkaller.appspot.com/bug?extid=3851eb8f18e56ea886e1
compiler: Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/cbc22554cbd8/disk-16fdf2c7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d03dacaa22f5/vmlinux-16fdf2c7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b3dc7f1264c1/Image-16fdf2c7.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3851eb...@syzkaller.appspotmail.com

watchdog: BUG: soft lockup - CPU#0 stuck for 28s! [kworker/0:4:4073]
Modules linked in:
irq event stamp: 80274
hardirqs last enabled at (80273): [<ffff8000081e6f9c>] queue_delayed_work_on+0x22c/0x324 kernel/workqueue.c:1719
hardirqs last disabled at (80274): [<ffff8000111a2130>] enter_el1_irq_or_nmi+0x10/0x1c arch/arm64/kernel/entry-common.c:227
softirqs last enabled at (75972): [<ffff80000819d0d8>] softirq_handle_end kernel/softirq.c:401 [inline]
softirqs last enabled at (75972): [<ffff80000819d0d8>] handle_softirqs+0xa4c/0xbf0 kernel/softirq.c:586
softirqs last disabled at (75929): [<ffff80000819c5d8>] __do_softirq kernel/softirq.c:592 [inline]
softirqs last disabled at (75929): [<ffff80000819c5d8>] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
softirqs last disabled at (75929): [<ffff80000819c5d8>] do_softirq+0xfc/0x1b0 kernel/softirq.c:459
CPU: 0 PID: 4073 Comm: kworker/0:4 Not tainted 5.15.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Workqueue: rcu_gp process_srcu
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:71 [inline]
pc : queue_delayed_work_on+0x24c/0x324 kernel/workqueue.c:1714
lr : queue_delayed_work_on+0x248/0x324 kernel/workqueue.c:1719
sp : ffff80001f3e79e0
x29: ffff80001f3e79e0 x28: ffff0001b42cc100 x27: dfff800000000000
x26: dfff800000000000 x25: 0000000000000000 x24: ffff80001ae134f8
x23: ffff0000c0021800 x22: 0000000000000000 x21: 0000000000000000
x20: 0000000000000008 x19: 0000000000000080 x18: 0000000000000002
x17: 0000000040000000 x16: ffff8000082bf2a4 x15: 0000000000000002
x14: 0000000000ff0100 x13: 1ffff0000282a06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000000 x9 : ffff8000081e6fb8
x8 : ffff0000c2280000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000000 x3 : ffff800008044e7c
x2 : 0000000000000006 x1 : 0000000000000080 x0 : 0000000000000000
Call trace:
arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline]
queue_delayed_work_on+0x24c/0x324 kernel/workqueue.c:1719
queue_delayed_work include/linux/workqueue.h:527 [inline]
srcu_reschedule kernel/rcu/srcutree.c:1313 [inline]
process_srcu+0xab8/0xc30 kernel/rcu/srcutree.c:1326
process_one_work+0x79c/0x1140 kernel/workqueue.c:2310
worker_thread+0x8f4/0x101c kernel/workqueue.c:2457
kthread+0x374/0x454 kernel/kthread.c:334
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.