rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13346/1:b..l P11552/1:b..l P6699/1:b..l P13324/1:b..l P12597/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=71865, q=384 ncpus=2)
task:syz-executor state:R running task stack:21064 pid:12597 tgid:12597 ppid:12588 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_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:unwind_next_frame+0x374/0x2390 arch/x86/kernel/unwind_orc.c:505
Code: ea 48 01 d2 48 01 f2 48 bd 00 00 00 00 00 fc ff df 0f 84 37 01 00 00 4c 8d 62 04 4c 8d 6a 05 4c 89 e0 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 6d 19 00 00 4c 89 e8 48 c1 e8 03 0f b6 04 28 84 c0 0f
RSP: 0018:ffffc9000b2377b8 EFLAGS: 00000a07
RAX: 0000000000000000 RBX: ffffffff8fbe3f08 RCX: ffffffff8fbe3f0c
RDX: ffffffff903e1282 RSI: ffffffff903e1246 RDI: ffffffff8be340a0
RBP: dffffc0000000000 R08: 000000000000000b R09: ffffffff8172c195
R10: ffffc9000b2378d8 R11: ffffffff81ac4020 R12: ffffffff903e1286
R13: ffffffff903e1287 R14: ffffc9000b237888 R15: ffffffff8fbe3f08
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
discard_slab mm/slub.c:2753 [inline]
__put_partials+0x156/0x1a0 mm/slub.c:3218
put_cpu_partial+0x17c/0x250 mm/slub.c:3293
__slab_free+0x2d5/0x3c0 mm/slub.c:4550
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4180 [inline]
slab_alloc_node mm/slub.c:4229 [inline]
kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4236
getname_flags+0xb8/0x540 fs/namei.c:146
user_path_at+0x24/0x60 fs/namei.c:3126
ksys_umount fs/namespace.c:2115 [inline]
__do_sys_umount fs/namespace.c:2123 [inline]
__se_sys_umount fs/namespace.c:2121 [inline]
__x64_sys_umount+0xee/0x160 fs/namespace.c:2121
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: 0033:0x7f31f2d8fe97
RSP: 002b:00007ffe272ae588 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f31f2d8fe97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe272ae640
RBP: 00007ffe272ae640 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe272af6d0
R13: 00007f31f2e11bdd R14: 00000000000bcebb R15: 00007ffe272af710
task:syz.5.1933 state:R running task stack:25288 pid:13324 tgid:13322 ppid:12274 task_flags:0x40054c 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]
zap_pte_range mm/memory.c:1756 [inline]
zap_pmd_range mm/memory.c:1818 [inline]
zap_pud_range mm/memory.c:1847 [inline]
zap_p4d_range mm/memory.c:1868 [inline]
unmap_page_range+0x3a79/0x4370 mm/memory.c:1889
unmap_single_vma mm/memory.c:1932 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:1976
exit_mmap+0x248/0xb50 mm/mmap.c:1280
__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
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f879558eb69
RSP: 002b:00007f87964710e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f87957b6088 RCX: 00007f879558eb69
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f87957b608c
RBP: 00007f87957b6080 R08: 7fffffffffffffff R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f87957b608c
R13: 0000000000000000 R14: 00007ffd21073120 R15: 00007ffd21073208
task:kworker/u8:16 state:R running task stack:21224 pid:6699 tgid:6699 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_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:412
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 eb 61 b9 f5 cc
RSP: 0018:ffffc9001cbffa18 EFLAGS: 00000293
RAX: ffffffff8b44b1d3 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff88801e3d3c00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88806a2c5940 R08: 0000000000000000 R09: ffffffff8b44b1a2
R10: dffffc0000000000 R11: fffffbfff1f44307 R12: dffffc0000000000
R13: ffffffff8b44b1a2 R14: ffff88807bb30d80 R15: 0000000000000328
rcu_read_lock include/linux/rcupdate.h:842 [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: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
task:syz-executor state:R running task stack:20872 pid:11552 tgid:11552 ppid:11533 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_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
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:ffffc900111f7088 EFLAGS: 00000206
RAX: 461f4447bded0b00 RBX: 0000000000000000 RCX: 461f4447bded0b00
RDX: 0000000000000000 RSI: ffffffff8db7a779 RDI: ffffffff8be34100
RBP: ffffffff822b2f9a R08: 0000000000000000 R09: ffffffff822b2f9a
R10: dffffc0000000000 R11: fffffbfff1f44307 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]
get_mem_cgroup_from_objcg+0x3a/0x1d0 include/linux/memcontrol.h:508
obj_cgroup_charge_pages mm/memcontrol.c:2798 [inline]
__memcg_kmem_charge_page+0xd1/0x240 mm/memcontrol.c:2844
__alloc_frozen_pages_noprof+0x1b5/0x370 mm/page_alloc.c:5165
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline]
alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2507
pagetable_alloc_noprof include/linux/mm.h:2904 [inline]
__pte_alloc_one_noprof include/asm-generic/pgalloc.h:75 [inline]
pte_alloc_one+0x21/0x170 arch/x86/mm/pgtable.c:18
__pte_alloc+0x25/0x1a0 mm/memory.c:452
copy_pte_range mm/memory.c:1107 [inline]
copy_pmd_range+0x6a91/0x71d0 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: 0033:0x7f817f9853d3
RSP: 002b:00007fffaed5a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f817f9853d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 00005555682957d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 00000000000bcdef R15: 00007fffaed5a260
task:syz.3.1938 state:R running task stack:26920 pid:13346 tgid:13343 ppid:5860 task_flags:0x400140 flags:0x00004002
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_irq include/linux/spinlock_api_smp.h:160 [inline]
_raw_spin_unlock_irq+0x45/0x50 kernel/locking/spinlock.c:202
bdi_split_work_to_wbs+0x564/0x8c0 fs/fs-writeback.c:1033
sync_inodes_sb+0x1ae/0xa10 fs/fs-writeback.c:2832
__iterate_supers+0x13d/0x290 fs/super.c:924
ksys_sync+0x94/0x150 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
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: 0033:0x7feef3f8eb69
RSP: 002b:00007feef4e32038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007feef41b5fa0 RCX: 00007feef3f8eb69
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007feef41b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007feef41b5fa0 R15: 00007ffda209bc98
rcu: rcu_preempt kthread starved for 10493 jiffies! g71865 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:26632 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 13345 Comm: syz.8.1940 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:taprio_set_budgets+0x38/0x3b0 net/sched/sch_taprio.c:660
Code: 49 89 d7 49 89 f6 48 89 fb 48 bd 00 00 00 00 00 fc ff df e8 2a 61 27 f8 49 89 dd 4c 8d 63 08 4c 89 e0 48 c1 e8 03 80 3c 28 00 <74> 08 4c 89 e7 e8 0e c0 8a f8 4d 8b 24 24 49 83 c4 40 4c 89 e0 48
RSP: 0000:ffffc90000007c00 EFLAGS: 00000046
RAX: 1ffff11004e50e59 RBX: ffff8880272872c0 RCX: ffff888079c59e00
RDX: 0000000000010000 RSI: ffff888058715800 RDI: ffff8880272872c0
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f7c R12: ffff8880272872c8
R13: ffff8880272872c0 R14: ffff888058715800 R15: ffff88805709f000
FS: 00007feaefcb26c0(0000) GS:ffff888125c43000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007feae4600000 CR3: 000000005fc5e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
advance_sched+0x963/0xc90 net/sched/sch_taprio.c:977
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5225
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 9f a8 e8 09 e8 5a 40 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0000:ffffc90002e27238 EFLAGS: 00000282
RAX: 972b83a94abeb800 RBX: 0000000000000000 RCX: 972b83a94abeb800
RDX: 0000000000000000 RSI: ffffffff8d98c137 RDI: ffffffff8be34100
RBP: ffffc90002e27290 R08: ffffffff8fa21837 R09: 1ffffffff1f44306
R10: dffffc0000000000 R11: fffffbfff1f44307 R12: ffff888079c59e00
R13: dffffc0000000000 R14: ffff8880252d1e00 R15: 0000000000000000
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x17a0/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
unix_wait_for_peer+0x1e9/0x2e0 net/unix/af_unix.c:1639
unix_dgram_sendmsg+0xb7a/0x1850 net/unix/af_unix.c:2273
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:729
____sys_sendmsg+0x52d/0x830 net/socket.c:2614
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
__sys_sendmmsg+0x227/0x430 net/socket.c:2757
__do_sys_sendmmsg net/socket.c:2784 [inline]
__se_sys_sendmmsg net/socket.c:2781 [inline]
__x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2781
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: 0033:0x7feaeed8eb69
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feaefcb2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007feaeefb5fa0 RCX: 00007feaeed8eb69
RDX: 0000000000000318 RSI: 00002000000bd000 RDI: 0000000000000004
RBP: 00007feaeee11df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007feaeefb5fa0 R15: 00007ffd81e1e928