rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5176/1:b..l P4320/1:b..l
	(detected by 0, t=10502 jiffies, g=20049, q=46)
task:kworker/u4:14   state:R  running task     stack:22640 pid: 4320 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 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:ffffc900031ffaa0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 91ebf2141ca16c00
RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f980
RBP: ffffc900031ffbc0 R08: dffffc0000000000 R09: 1ffffffff203a818
R10: dffffc0000000000 R11: fffffbfff203a819 R12: ffffffff8c31eaa0
R13: 1ffff9200063ff60 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 rcu_read_lock include/linux/rcupdate.h:740 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0xc9/0x5c0 net/batman-adv/network-coding.c:723
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
task:udevd           state:R  running task     stack:24824 pid: 5176 ppid:  3560 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571
 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6596
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
 _raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202
 spin_unlock_irq include/linux/spinlock.h:414 [inline]
 loop_queue_work drivers/block/loop.c:1069 [inline]
 loop_queue_rq+0x9e0/0xac0 drivers/block/loop.c:2202
 __blk_mq_issue_directly block/blk-mq.c:2015 [inline]
 __blk_mq_try_issue_directly+0x497/0x820 block/blk-mq.c:2071
 blk_mq_request_issue_directly block/blk-mq.c:2119 [inline]
 blk_mq_try_issue_list_directly+0x1a1/0x530 block/blk-mq.c:2137
 blk_mq_sched_insert_requests+0x2d6/0x5c0 block/blk-mq-sched.c:512
 blk_mq_flush_plug_list+0x59b/0x690 block/blk-mq.c:1972
 blk_flush_plug_list+0x404/0x450 block/blk-core.c:1734
 blk_finish_plug+0x59/0x80 block/blk-core.c:1751
 read_pages+0x4d2/0x930 mm/readahead.c:150
 page_cache_ra_unbounded+0x838/0x940 mm/readahead.c:239
 do_page_cache_ra mm/readahead.c:269 [inline]
 force_page_cache_ra+0x3e5/0x440 mm/readahead.c:301
 page_cache_sync_readahead include/linux/pagemap.h:833 [inline]
 filemap_get_pages mm/filemap.c:2551 [inline]
 filemap_read+0x5de/0x2540 mm/filemap.c:2634
 blkdev_read_iter+0x11d/0x150 block/fops.c:563
 call_read_iter include/linux/fs.h:2167 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0x759/0xd60 fs/read_write.c:485
 ksys_read+0x152/0x260 fs/read_write.c:623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f11d1b53407
RSP: 002b:00007fffc0f09cb0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f11d1a65880 RCX: 00007f11d1b53407
RDX: 0000000000000200 RSI: 00007f11d10fc000 RDI: 0000000000000009
RBP: 0000562c9d2ee050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000040000 R14: 0000562c9d2e15d8 R15: 00007f11d22a939c
 </TASK>
rcu: rcu_preempt kthread starved for 10557 jiffies! g20049 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:28112 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5921 Comm: syz.4.347 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:56 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x4e/0x290 mm/kasan/generic.c:189
Code: e8 2f 41 81 f8 ff ff 01 00 0f 82 fa 01 00 00 49 bc 01 00 00 00 00 fc ff df 49 89 fe 49 c1 ee 03 49 ba 00 00 00 00 00 fc ff df <4f> 8d 1c 16 4c 8d 44 3e ff 4d 89 c1 49 c1 e9 03 4b 8d 1c 21 49 89
RSP: 0018:ffffc900033ffab0 EFLAGS: 00000802
RAX: 0000000000000001 RBX: 00000000000000a2 RCX: ffffffff815d0aec
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901d40d0
RBP: ffffc900033ffd30 R08: 000000000001ffff R09: 1ffffffff203a81a
R10: dffffc0000000000 R11: fffffbfff203a81b R12: dffffc0000000001
R13: ffff888028135940 R14: 1ffffffff203a81a R15: ffff888028136430
FS:  0000555589e72500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000004000 CR3: 000000005b369000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 hlock_class kernel/locking/lockdep.c:197 [inline]
 check_wait_context kernel/locking/lockdep.c:4687 [inline]
 __lock_acquire+0x5dc/0x7d10 kernel/locking/lockdep.c:4962
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 do_write_seqcount_begin_nested include/linux/seqlock.h:519 [inline]
 do_write_seqcount_begin include/linux/seqlock.h:545 [inline]
 vtime_user_exit+0x95/0x3e0 kernel/sched/cputime.c:725
 __context_tracking_exit+0x4c/0x80 kernel/context_tracking.c:160
 user_exit_irqoff include/linux/context_tracking.h:47 [inline]
 __enter_from_user_mode kernel/entry/common.c:22 [inline]
 syscall_enter_from_user_mode+0x56/0x70 kernel/entry/common.c:110
 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f459a452517
Code: 8d 3d 12 8b 0b 00 e8 58 1d fa ff e8 a3 87 00 00 0f 1f 00 b8 68 00 00 00 0f 05 c3 0f 1f 84 00 00 00 00 00 b8 27 00 00 00 0f 05 <c3> 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007ffde4d9e908 EFLAGS: 00000202 ORIG_RAX: 0000000000000027
RAX: ffffffffffffffda RBX: 00007ffde4d9ea70 RCX: 00007f459a452517
RDX: 00007ffde4d9e940 RSI: 00007ffde4d9ea70 RDI: 0000000000000021
RBP: 0000000000000000 R08: 000b2914f58a44f6 R09: 0000000000000000
R10: 00007ffde4d9eff0 R11: 0000000000000202 R12: 00007ffde4d9f010
R13: 00007f459a6d1fac R14: 000000000003442a R15: 00007ffde4d9eff0
 </TASK>