rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9/1:b..l P10403/1:b..l
(detected by 1, t=10502 jiffies, g=43257, q=355 ncpus=2)
task:syz.0.1549 state:R running task stack:26608 pid:10403 ppid:4274 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6875
irqentry_exit+0x63/0x70 kernel/entry/common.c:442
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5682
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc90004e5f660 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0f09321ff2fc6d00
RDX: 0000000000000000 RSI: ffffffff8a8c2a20 RDI: ffffffff8adf68a0
RBP: ffffc90004e5f778 R08: dffffc0000000000 R09: 1ffffffff2161e48
R10: dffffc0000000000 R11: fffffbfff2161e49 R12: 0000000000000000
R13: 1ffff920009cbed8 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
blk_cgroup_congested+0x37/0x220 block/blk-cgroup.c:2037
__cgroup_throttle_swaprate+0x6d/0x1a0 mm/swapfile.c:3678
cgroup_throttle_swaprate include/linux/swap.h:672 [inline]
folio_throttle_swaprate include/linux/swap.h:681 [inline]
shmem_add_to_page_cache+0x9aa/0x1c90 mm/shmem.c:717
shmem_get_folio_gfp+0x1663/0x35e0 mm/shmem.c:1971
shmem_get_folio mm/shmem.c:2072 [inline]
shmem_write_begin+0xee/0x3f0 mm/shmem.c:2556
generic_perform_write+0x2fa/0x5c0 mm/filemap.c:3862
__generic_file_write_iter+0x148/0x2a0 mm/filemap.c:3960
generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989
call_write_iter include/linux/fs.h:2271 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x482/0x9a0 fs/read_write.c:584
ksys_write+0x14d/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc77615e98e
RSP: 002b:00007fc77711dda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc77711e6c0 RCX: 00007fc77615e98e
RDX: 0000000000400000 RSI: 00007fc76bff7000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fc77711dee0 R14: 00007fc77711dea0 R15: 00007fc76bff7000
task:kworker/u4:0 state:R running task stack:21808 pid:9 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6875
irqentry_exit+0x63/0x70 kernel/entry/common.c:442
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5682
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc900000e7ac0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 77413a0e8ddce300
RDX: 0000000000000000 RSI: ffffffff8a8c2a20 RDI: ffffffff8adf68a0
RBP: ffffc900000e7bc8 R08: dffffc0000000000 R09: 1ffffffff2161e48
R10: dffffc0000000000 R11: fffffbfff2161e49 R12: 0000000000000001
R13: 1ffff9200001cf64 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xeb/0x600 net/batman-adv/network-coding.c:719
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
rcu: rcu_preempt kthread starved for 10563 jiffies! g43257 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:27600 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x303/0x1350 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742
Code: 48 89 df e8 37 f3 96 f7 e9 44 ff ff ff e8 7d 03 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 77 23 4a 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffc90000177de8 EFLAGS: 000002c6
RAX: 61633203769a7600 RBX: ffffffff8a3c8957 RCX: 61633203769a7600
RDX: 0000000000000001 RSI: ffffffff8a8c18a0 RDI: ffffffff8adf68a0
RBP: ffffc90000177f20 R08: ffff8880b8f357cb R09: 1ffff110171e6af9
R10: dffffc0000000000 R11: ffffed10171e6afa R12: 0000000000000000
R13: dffffc0000000000 R14: ffff888017739e00 R15: 1ffff9200002efc8
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f01e6625fac CR3: 0000000028786000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
default_idle_call+0x84/0xc0 kernel/sched/idle.c:109
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x250/0x680 kernel/sched/idle.c:323
cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:422
start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281
secondary_startup_64_no_verify+0xcf/0xdb