rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12/1:b..l P8957/1:b..l P7317/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=34153, q=257 ncpus=2)
task:syz-executor state:R running task stack:21032 pid:7317 tgid:7317 ppid:7304 task_flags:0x400140 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
copy_pte_range mm/memory.c:1201 [inline]
copy_pmd_range+0x68c6/0x71d0 mm/memory.c:1261
copy_pud_range mm/memory.c:1298 [inline]
copy_p4d_range mm/memory.c:1322 [inline]
copy_page_range+0xc14/0x1270 mm/memory.c:1410
dup_mmap+0xf57/0x1ac0 mm/mmap.c:1834
dup_mm kernel/fork.c:1485 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1537
copy_process+0x1706/0x3c00 kernel/fork.c:2175
kernel_clone+0x21e/0x840 kernel/fork.c:2605
__do_sys_clone kernel/fork.c:2748 [inline]
__se_sys_clone kernel/fork.c:2732 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2732
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c3f9853d3
RSP: 002b:00007ffde01bb508 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5c3f9853d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 00005555932ee7d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 000000000006afa1 R15: 00007ffde01bb6a0
task:rm state:R running task stack:23656 pid:8957 tgid:8957 ppid:8904 task_flags:0x40000c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 fb 72 00 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000ce272f8 EFLAGS: 00000206
RAX: 0290282878d7bb00 RBX: 0000000000000000 RCX: 0290282878d7bb00
RDX: 0000000000000000 RSI: ffffffff8db7a779 RDI: ffffffff8be34100
RBP: ffffffff8172c195 R08: 0000000000000000 R09: ffffffff8172c195
R10: ffffc9000ce274b8 R11: ffffffff81ac4020 R12: 0000000000000002
R13: ffffffff8e139f20 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548
slab_free_hook mm/slub.c:2378 [inline]
slab_free mm/slub.c:4680 [inline]
kmem_cache_free+0x2f6/0x400 mm/slub.c:4782
anon_vma_free mm/rmap.c:137 [inline]
__put_anon_vma+0x12b/0x2d0 mm/rmap.c:2764
put_anon_vma include/linux/rmap.h:117 [inline]
unlink_anon_vmas+0x503/0x670 mm/rmap.c:444
free_pgtables+0x72b/0x9c0 mm/memory.c:413
exit_mmap+0x444/0xb50 mm/mmap.c:1291
__mmput+0x118/0x430 kernel/fork.c:1129
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
__do_sys_exit_group kernel/exit.c:1113 [inline]
__se_sys_exit_group kernel/exit.c:1111 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f845b05c6c5
RSP: 002b:00007fff32791718 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f845b15dfe8 RCX: 00007f845b05c6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000001 R08: 00007fff327916a8 R09: 0000000000000000
R10: 00007fff32791540 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f845b15c680 R15: 00007f845b15e000
task:kworker/u8:0 state:R running task stack:22184 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:217
Code: 08 d0 9d 92 65 8b 15 d8 1c de 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 00 <83> fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 8d 7e 01 8b 89 1c
RSP: 0018:ffffc90000117a18 EFLAGS: 00000246
RAX: ffffffff8b44b2e1 RBX: 0000000000000001 RCX: ffff88801ceada00
RDX: 0000000000000000 RSI: ffffffff8be340e0 RDI: ffffffff8be340a0
RBP: fffffffffffffe38 R08: 0000000000000000 R09: ffffffff8b44b1a2
R10: dffffc0000000000 R11: ffffffff8b44b0d0 R12: dffffc0000000000
R13: ffffffff8b44b1a2 R14: ffff888030148d80 R15: 00000000000001d4
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
batadv_nc_worker+0x211/0x610 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 9951 jiffies! g34153 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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-next-20250731-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 53 e8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 06 11 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 83d45b44c0004800 RBX: ffffffff81968308 RCX: 83d45b44c0004800
RDX: 0000000000000001 RSI: ffffffff8d98c137 RDI: ffffffff8be34100
RBP: ffffc90000197f20 R08: ffff8880b8732f5b R09: 1ffff110170e65eb
R10: dffffc0000000000 R11: ffffed10170e65ec R12: ffffffff8fa21830
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a58b40
FS: 0000000000000000(0000) GS:ffff888125d43000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f236942aa6c CR3: 000000002f3ce000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
common_startup_64+0x13e/0x147
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6176 Comm: kworker/u8:10 Not tainted 6.16.0-next-20250731-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: 8b 3d b4 91 fb 0b 48 89 de 5b e9 f3 8e 58 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 d0 9d 92 65 8b 15 d8 1c de 10 81 e2 00 01 ff 00
RSP: 0018:ffffc9000aff7738 EFLAGS: 00000006
RAX: ffffffff85530281 RBX: 0000000000000200 RCX: ffff88802bceda00
RDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000000
RBP: ffffc9000aff7830 R08: ffffc9000aff78ff R09: 0000000000000000
R10: ffffc9000aff78c0 R11: fffff520015fef20 R12: dffffc0000000000
R13: 0000000000000006 R14: ffff888055c48000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125d43000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000032000 CR3: 000000000df36000 CR4: 00000000003526f0
Call Trace:
crng_make_state+0xe1/0x700 drivers/char/random.c:368
_get_random_bytes+0xd5/0x210 drivers/char/random.c:406
eth_random_addr include/linux/etherdevice.h:238 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:770 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
nsim_dev_trap_report_work+0x35d/0xb80 drivers/net/netdevsim/dev.c:866
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245