rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2952/1:b..l P11840/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=58129, q=138 ncpus=2)
task:syz.1.1752 state:R running task stack:27016 pid:11840 ppid:5770 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:1357
exit_mm+0x24a/0x350 kernel/exit.c:570
do_exit+0x8dd/0x2460 kernel/exit.c:871
do_group_exit+0x21b/0x2d0 kernel/exit.c:1026
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+0x61/0xb0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2faf19ce59
RSP: 002b:00007ffe32e4e488 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffff92 RBX: 00000000000bb5ab RCX: 00007f2faf19ce59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2faf41609c
RBP: 000000000000015e R08: 0000000000745a16 R09: 0000000000000000
R10: 00007ffe32e4e590 R11: 0000000000000246 R12: 00007ffe32e4e5b0
R13: 00007f2faf41609c R14: 00000000000bb709 R15: 00007ffe32e4e590
task:kworker/u4:7 state:R running task stack:20104 pid:2952 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
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:193 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x36/0x90 kernel/kcov.c:313
Code: 60 8a 7c 7e 65 8b 0d 61 8a 7c 7e 81 e1 00 01 ff 00 74 11 81 f9 00 01 00 00 75 5b 83 ba 1c 16 00 00 00 74 52 8b 8a f8 15 00 00 <83> f9 03 75 47 48 8b 8a 00 16 00 00 44 8b 8a fc 15 00 00 49 c1 e1
RSP: 0018:ffffc9000bf17b58 EFLAGS: 00000246
RAX: ffffffff8a4e3973 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff88802bf21e00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff888030a21818 R08: dffffc0000000000 R09: 1ffffffff2238ea0
R10: dffffc0000000000 R11: fffffbfff2238ea1 R12: dffffc0000000000
R13: ffffffff8a4e3942 R14: ffff888060450c80 R15: 0000000000000303
rcu_read_lock include/linux/rcupdate.h:787 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0x103/0x610 net/batman-adv/network-coding.c:719
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 10551 jiffies! g58129 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:27656 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: b9 20 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 c3 54 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: 89497fbf24652b00 RBX: ffffffff8162affd RCX: 89497fbf24652b00
RDX: 0000000000000001 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9860
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: 00007f6e5a6e0d58 CR3: 00000000314ec000 CR4: 00000000003526f0
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+0x33d/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:840
start_kernel+0x459/0x4e0 init/main.c:1085
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