[v5.15] INFO: rcu detected stall in batadv_bla_periodic_work

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 584a40a22cb9 Linux 5.15.168
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12008287980000
kernel config: https://syzkaller.appspot.com/x/.config?x=d0f9f3fba4f42ea2
dashboard link: https://syzkaller.appspot.com/bug?extid=0da7e747dc3186026cef
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/36df6ced99e4/disk-584a40a2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/967e3c14b32c/vmlinux-584a40a2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9def349eac49/Image-584a40a2.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0da7e7...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4027/1:b..l P4106/1:b..l
(detected by 0, t=10502 jiffies, g=4565, q=235)
task:kworker/u4:8 state:R running task stack: 0 pid: 4106 ppid: 2 flags:0x00000008
Workqueue: bat_events batadv_bla_periodic_work
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5027 [inline]
__schedule+0xf10/0x1e48 kernel/sched/core.c:6373
preempt_schedule_irq+0x90/0x274 kernel/sched/core.c:6777
arm64_preempt_schedule_irq+0x174/0x2c4 arch/arm64/kernel/entry-common.c:260
el1_interrupt+0x40/0x58 arch/arm64/kernel/entry-common.c:463
el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470
el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522
check_kcov_mode kernel/kcov.c:172 [inline]
__sanitizer_cov_trace_pc+0x74/0xac kernel/kcov.c:206
rcu_read_lock include/linux/rcupdate.h:739 [inline]
batadv_bla_purge_claims+0xf0/0x658 net/batman-adv/bridge_loop_avoidance.c:1288
batadv_bla_periodic_work+0xa0/0xa8c net/batman-adv/bridge_loop_avoidance.c:1443
process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
worker_thread+0x910/0x1034 kernel/workqueue.c:2457
kthread+0x37c/0x45c kernel/kthread.c:334
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
task:syz-executor state:R running task stack: 0 pid: 4027 ppid: 4020 flags:0x0000000c
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5027 [inline]
__schedule+0xf10/0x1e48 kernel/sched/core.c:6373
preempt_schedule_notrace+0xc4/0x1a8 kernel/sched/core.c:6628
rcu_lockdep_current_cpu_online+0x1a4/0x21c kernel/rcu/tree.c:1175
rcu_read_lock_held_common kernel/rcu/update.c:112 [inline]
rcu_read_lock_held+0x20/0x50 kernel/rcu/update.c:309
xa_entry include/linux/xarray.h:1182 [inline]
xas_find+0x4a4/0x8f0 lib/xarray.c:1266
find_get_entry+0x74/0x274 mm/filemap.c:1978
find_lock_entries+0x600/0x9f8 mm/filemap.c:2092
shmem_undo_range+0x24c/0x1460 mm/shmem.c:943
shmem_truncate_range mm/shmem.c:1063 [inline]
shmem_evict_inode+0x1c4/0x844 mm/shmem.c:1145
evict+0x418/0x894 fs/inode.c:622
iput_final fs/inode.c:1744 [inline]
iput+0x744/0x824 fs/inode.c:1770
dentry_unlink_inode+0x37c/0x4bc fs/dcache.c:380
__dentry_kill+0x324/0x5e4 fs/dcache.c:586
dentry_kill+0xc8/0x250
dput+0x21c/0x458 fs/dcache.c:893
__fput+0x494/0x800 fs/file_table.c:288
____fput+0x20/0x30 fs/file_table.c:308
task_work_run+0x130/0x1e4 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
do_notify_resume+0x262c/0x32b8 arch/arm64/kernel/signal.c:946
prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline]
el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:609
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
rcu: rcu_preempt kthread starved for 10507 jiffies! g4565 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:R running task stack: 0 pid: 15 ppid: 2 flags:0x00000008
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5027 [inline]
__schedule+0xf10/0x1e48 kernel/sched/core.c:6373
schedule+0x11c/0x1c8 kernel/sched/core.c:6456
schedule_timeout+0x1d8/0x344 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x26c/0x13d4 kernel/rcu/tree.c:1972
rcu_gp_kthread+0xc4/0x2c4 kernel/rcu/tree.c:2145
kthread+0x37c/0x45c kernel/kthread.c:334
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
rcu: Stack dump where RCU GP kthread last ran:
Task dump for CPU 1:
task:syz.1.11 state:R running task stack: 0 pid: 4145 ppid: 4023 flags:0x00000001
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
0xfffff00002956069


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[syzbot]

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