[v6.1] INFO: rcu detected stall in batadv_iv_send_outstanding_bat_ogm_packet (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4078fa637fcd Linux 6.1.91
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=10e3b4f0980000
kernel config: https://syzkaller.appspot.com/x/.config?x=715ba80acfd3def4
dashboard link: https://syzkaller.appspot.com/bug?extid=c9aac8e0e280f2968a2e
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/2443dfe91c62/disk-4078fa63.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/12dbc2af3348/vmlinux-4078fa63.xz
kernel image: https://storage.googleapis.com/syzbot-assets/da3589238e32/bzImage-4078fa63.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c9aac8...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=f9dc/1/0x4000000000000000 softirq=32431/32432 fqs=0
(detected by 1, t=10505 jiffies, g=44793, q=159 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 8887 Comm: kworker/u4:11 Not tainted 6.1.91-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xc3/0x130 kernel/locking/spinlock.c:194
Code: 4c 89 f7 e8 8f e2 4c f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 f2 e1 4c f7 f6 44 24 21 02 <75> 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 e8 d7 28 c9 f6
RSP: 0018:ffffc90000007ca0 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 1ffff92000000f98 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff91ea26f0
RBP: ffffc90000007d28 R08: dffffc0000000000 R09: fffffbfff23d44df
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff92000000f94 R14: ffffc90000007cc0 R15: 0000000000000046
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa7e0779bf8 CR3: 000000001fb91000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<IRQ>
debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline]
debug_deactivate+0x1d/0x280 kernel/time/hrtimer.c:481
__run_hrtimer kernel/time/hrtimer.c:1654 [inline]
__hrtimer_run_queues+0x334/0xe50 kernel/time/hrtimer.c:1750
hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
__sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112
sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:__rcu_read_unlock+0xa/0x100 kernel/rcu/tree_plugin.h:419
Code: e1 07 80 c1 03 38 c1 7c b0 4c 89 ff e8 3f fa 6d 00 eb a6 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 55 41 57 41 56 41 55 41 54 53 <49> bc 00 00 00 00 00 fc ff df 65 4c 8b 35 94 5c 8e 7e 4d 8d ae 3c
RSP: 0018:ffffc90006347a28 EFLAGS: 00000293
RAX: ffffffff8a5709d2 RBX: 0000000000000001 RCX: ffff88805d353b80
RDX: 0000000000000000 RSI: ffffffff8b3d4540 RDI: ffffffff8b3d4500
RBP: ffffc90006347b98 R08: ffffffff8a5709c0 R09: fffffbfff2093845
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88801f1bc800
R13: ffff88805a970ec0 R14: dffffc0000000000 R15: ffff88807e090128
rcu_read_unlock include/linux/rcupdate.h:823 [inline]
batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:772 [inline]
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:826 [inline]
batadv_iv_ogm_schedule+0x6e3/0x1090 net/batman-adv/bat_iv_ogm.c:869
batadv_iv_send_outstanding_bat_ogm_packet+0x6fa/0x800 net/batman-adv/bat_iv_ogm.c:1713
process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
rcu: rcu_preempt kthread starved for 10505 jiffies! g44793 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:27032 pid:16 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 8976 Comm: kworker/u4:12 Not tainted 6.1.91-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0x1fb0/0x3460 kernel/smp.c:998
Code: 2f 44 89 ee 83 e6 01 31 ff e8 ec 42 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 77 3f 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff
RSP: 0018:ffffc90009cf75a0 EFLAGS: 00000293
RAX: ffffffff817f4dfb RBX: 1ffff1101730859d RCX: ffff888079d00000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90009cf7980 R08: ffffffff817f4dc4 R09: fffffbfff2093845
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b9842ce8
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbfe8978198 CR3: 000000000ce8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
</IRQ>
<TASK>
on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:1334 [inline]
text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1534
text_poke_flush arch/x86/kernel/alternative.c:1725 [inline]
text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1732
arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:177
static_key_enable+0x16/0x20 kernel/jump_label.c:190
toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:804
process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>


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