rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6349/1:b..l P2934/1:b..l P6901/1:b..l P7541/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=27017, q=172 ncpus=2)
task:syz.1.357 state:R running task stack:24328 pid:7541 ppid:5768 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867
preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1523 [inline]
zap_pmd_range mm/memory.c:1571 [inline]
zap_pud_range mm/memory.c:1600 [inline]
zap_p4d_range mm/memory.c:1621 [inline]
unmap_page_range+0x2315/0x3000 mm/memory.c:1642
unmap_vmas+0x286/0x3f0 mm/memory.c:1732
exit_mmap+0x238/0xb90 mm/mmap.c:3302
__mmput+0x118/0x3c0 kernel/fork.c:1356
exit_mm+0x1f2/0x2c0 kernel/exit.c:569
do_exit+0x8dd/0x2460 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
get_signal+0x12fc/0x13f0 kernel/signal.c:2902
arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8c4e99cdd9
RSP: 002b:00007fff33268e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffdfc RBX: 000000000005b2cb RCX: 00007f8c4e99cdd9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8c4ec1609c
RBP: 0000000000000032 R08: 0000000000745d1e R09: 0000000000000000
R10: 00007fff33268f70 R11: 0000000000000246 R12: 00007fff33268f90
R13: 00007f8c4ec1609c R14: 000000000005b2fd R15: 00007fff33268f70
task:udevd state:R running task stack:25704 pid:6901 ppid:5136 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867
preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1523 [inline]
zap_pmd_range mm/memory.c:1571 [inline]
zap_pud_range mm/memory.c:1600 [inline]
zap_p4d_range mm/memory.c:1621 [inline]
unmap_page_range+0x2315/0x3000 mm/memory.c:1642
unmap_vmas+0x286/0x3f0 mm/memory.c:1732
exit_mmap+0x238/0xb90 mm/mmap.c:3302
__mmput+0x118/0x3c0 kernel/fork.c:1356
exit_mm+0x1f2/0x2c0 kernel/exit.c:569
do_exit+0x8dd/0x2460 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4efe0f16c5
RSP: 002b:00007ffdb91c3ec8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055ecd016bf80 RCX: 00007f4efe0f16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055ecd0147910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdb91c3f10 R14: 0000000000000000 R15: 0000000000000000
task:kworker/u4:6 state:R running task stack:22248 pid:2934 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
preempt_schedule_notrace+0xdd/0x110 kernel/sched/core.c:6960
preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:46
rcu_is_watching+0x7a/0xb0 kernel/rcu/tree.c:701
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0xc6/0x420 kernel/locking/lockdep.c:5725
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
percpu_ref_put_many+0x3e/0x240 include/linux/percpu-refcount.h:330
percpu_ref_put include/linux/percpu-refcount.h:351 [inline]
blk_mq_dispatch_plug_list block/blk-mq.c:2842 [inline]
blk_mq_flush_plug_list+0x1591/0x1770 block/blk-mq.c:2891
__blk_flush_plug+0x3e4/0x460 block/blk-core.c:1179
blk_flush_plug include/linux/blkdev.h:1008 [inline]
io_schedule_prepare kernel/sched/core.c:8992 [inline]
io_schedule+0x78/0xd0 kernel/sched/core.c:9022
rq_qos_wait+0x229/0x300 block/blk-rq-qos.c:282
__wbt_wait block/blk-wbt.c:595 [inline]
wbt_wait+0x34b/0x5d0 block/blk-wbt.c:659
__rq_qos_throttle+0x65/0xb0 block/blk-rq-qos.c:66
rq_qos_throttle block/blk-rq-qos.h:151 [inline]
blk_mq_get_new_requests block/blk-mq.c:2955 [inline]
blk_mq_submit_bio+0x88f/0x2160 block/blk-mq.c:3056
__submit_bio+0x12b/0x260 block/blk-core.c:610
__submit_bio_noacct_mq block/blk-core.c:689 [inline]
submit_bio_noacct_nocheck+0x6e8/0x9c0 block/blk-core.c:718
ext4_io_submit fs/ext4/page-io.c:389 [inline]
io_submit_add_bh fs/ext4/page-io.c:430 [inline]
ext4_bio_write_folio+0x109e/0x2250 fs/ext4/page-io.c:578
mpage_submit_folio+0x237/0x3c0 fs/ext4/inode.c:1910
mpage_process_page_bufs+0x6e1/0x8f0 fs/ext4/inode.c:2023
mpage_prepare_extent_to_map+0xe06/0x1cc0 fs/ext4/inode.c:2531
ext4_do_writepages+0xb44/0x3990 fs/ext4/inode.c:2673
ext4_writepages+0x1dd/0x350 fs/ext4/inode.c:2809
do_writepages+0x3b3/0x630 mm/page-writeback.c:2575
__writeback_single_inode+0x153/0xec0 fs/fs-writeback.c:1635
writeback_sb_inodes+0x7cd/0xf50 fs/fs-writeback.c:1926
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:1997
wb_writeback+0x47e/0xbf0 fs/fs-writeback.c:2107
wb_check_old_data_flush fs/fs-writeback.c:2211 [inline]
wb_do_writeback fs/fs-writeback.c:2264 [inline]
wb_workfn+0xad7/0xe60 fs/fs-writeback.c:2292
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
task:kworker/u4:10 state:R running task stack:22984 pid:6349 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x17/0x60 kernel/kcov.c:216
Code: 48 8b 3d dc f9 03 0d 48 89 de 5b e9 d3 67 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d b0 93 7c 7e 65 8b 15 b1 93 7c 7e <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00
RSP: 0018:ffffc900035379b8 EFLAGS: 00000202
RAX: ffffffff8a495423 RBX: ffff88814c2c82d0 RCX: ffff88802d9d9e00
RDX: 0000000080000000 RSI: ffffffff8b1c8f80 RDI: ffffffff8b1c8f40
RBP: ffffc90003537b00 R08: dffffc0000000000 R09: 1ffffffff2238ca0
R10: dffffc0000000000 R11: fffffbfff2238ca1 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff88801db268a4
rcu_read_lock include/linux/rcupdate.h:787 [inline]
batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:756 [inline]
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:827 [inline]
batadv_iv_ogm_schedule+0x433/0xf10 net/batman-adv/bat_iv_ogm.c:870
batadv_iv_send_outstanding_bat_ogm_packet+0x733/0x850 net/batman-adv/bat_iv_ogm.c:1714
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: rcu_preempt kthread starved for 10497 jiffies! g27017 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:26960 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: 19 21 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d e3 d3 41 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80
RSP: 0018:ffffffff8ce07d80 EFLAGS: 000002c6
RAX: 20b5698bb97a7c00 RBX: ffffffff8162a8f1 RCX: 20b5698bb97a7c00
RDX: 0000000000000001 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c8fa0
RBP: ffffffff8ce07eb8 R08: ffff8880b8e36b2b R09: 1ffff110171c6d65
R10: dffffc0000000000 R11: ffffed10171c6d66 R12: 1ffffffff19c0fbc
R13: dffffc0000000000 R14: 1ffffffff19d2688 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4efe821e80 CR3: 00000000646bf000 CR4: 00000000003506f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:753
default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
cpuidle_idle_call kernel/sched/idle.c:178 [inline]
do_idle+0x221/0x590 kernel/sched/idle.c:302
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
rest_init+0x2e2/0x300 init/main.c:744
arch_call_rest_init+0xe/0x10 init/main.c:841
start_kernel+0x459/0x4e0 init/main.c:1086
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536
secondary_startup_64_no_verify+0x179/0x17b
hrtimer: interrupt took 1692178909 ns