GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P23246/1:b..l P20169/1:b..l P24817/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=117645, q=1868 ncpus=2)
task:udevd state:R running task stack:26688 pid:24817 tgid:24817 ppid:5216 task_flags:0x40014c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:unwind_next_frame+0x674/0x20a0 arch/x86/kernel/unwind_orc.c:581
Code: 85 a1 16 00 00 83 e0 07 38 c2 40 0f 9e c6 84 d2 0f 95 c0 40 84 c6 0f 85 8a 16 00 00 4c 0f bf 31 4d 01 fe 0f b6 41 05 83 e0 07 <3c> 03 0f 84 9c 05 00 00 3c 04 0f 84 d5 04 00 00 3c 02 0f 84 4e 06
RSP: 0018:ffffc90004fc74e8 EFLAGS: 00000202
RAX: 0000000000000002 RBX: 0000000000000001 RCX: ffffffff914f42c6
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc90004fc75a0 R08: ffffffff914f42ca R09: 0000000000000000
R10: ffffc90004fc7558 R11: 00000000000121b6 R12: ffffc90004fc75a8
R13: ffffc90004fc7558 R14: ffffc90004fc78e0 R15: ffffc90004fc78b8
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:356
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+0x1cb/0x3b0 mm/slub.c:4236
kmem_alloc_batch+0x49/0x170 lib/debugobjects.c:371
fill_pool lib/debugobjects.c:403 [inline]
debug_objects_fill_pool lib/debugobjects.c:725 [inline]
debug_objects_fill_pool+0x23f/0x520 lib/debugobjects.c:697
debug_object_activate+0x10b/0x4c0 lib/debugobjects.c:814
debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
__call_rcu_common.constprop.0+0x35/0xa10 kernel/rcu/tree.c:3108
slab_free_hook mm/slub.c:2381 [inline]
slab_free mm/slub.c:4680 [inline]
kmem_cache_free+0x16d/0x4d0 mm/slub.c:4782
exit_mmap+0x511/0xb90 mm/mmap.c:1305
__mmput+0x12a/0x410 kernel/fork.c:1130
mmput+0x62/0x70 kernel/fork.c:1152
exit_mm kernel/exit.c:582 [inline]
do_exit+0x7c7/0x2bf0 kernel/exit.c:949
do_group_exit+0xd3/0x2a0 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+0x3e/0x50 kernel/exit.c:1111
x64_sys_call+0x14fa/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f74876f16c5
RSP: 002b:00007ffff4348a38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00005591a1ae69c0 RCX: 00007f74876f16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 00005591a18902c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffff4348a80 R14: 0000000000000000 R15: 0000000000000000
task:udevd state:R running task stack:26688 pid:20169 tgid:20169 ppid:5216 task_flags:0x40014c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145
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+0x3e/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+0xf77/0x42c0 mm/memory.c:1889
unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:1932
unmap_vmas+0x218/0x470 mm/memory.c:1976
exit_mmap+0x1b9/0xb90 mm/mmap.c:1280
__mmput+0x12a/0x410 kernel/fork.c:1130
mmput+0x62/0x70 kernel/fork.c:1152
exit_mm kernel/exit.c:582 [inline]
do_exit+0x7c7/0x2bf0 kernel/exit.c:949
do_group_exit+0xd3/0x2a0 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+0x3e/0x50 kernel/exit.c:1111
x64_sys_call+0x14fa/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f74876f16c5
RSP: 002b:00007ffff4348a38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00005591a1ae1490 RCX: 00007f74876f16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 00005591a18902c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffff4348a80 R14: 0000000000000000 R15: 0000000000000000
task:udevd state:R running task stack:26688 pid:23246 tgid:23246 ppid:5216 task_flags:0x40014c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145
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+0x3e/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+0xf77/0x42c0 mm/memory.c:1889
unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:1932
unmap_vmas+0x218/0x470 mm/memory.c:1976
exit_mmap+0x1b9/0xb90 mm/mmap.c:1280
__mmput+0x12a/0x410 kernel/fork.c:1130
mmput+0x62/0x70 kernel/fork.c:1152
exit_mm kernel/exit.c:582 [inline]
do_exit+0x7c7/0x2bf0 kernel/exit.c:949
do_group_exit+0xd3/0x2a0 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+0x3e/0x50 kernel/exit.c:1111
x64_sys_call+0x14fa/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f74876f16c5
RSP: 002b:00007ffff4348a38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00005591a1ae26c0 RCX: 00007f74876f16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 00005591a18902c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffff4348a80 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 9399 jiffies! g117645 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7058
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
kthread+0x3c2/0x780 kernel/kthread.c:463
ret_from_fork+0x5d7/0x6f0 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: 26965 Comm: syz.7.5826 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0x45/0x2f0 kernel/locking/lockdep.c:5879
Code: b9 7f 3e 12 48 89 44 24 10 31 c0 0f 1f 44 00 00 65 8b 05 d2 7f 3e 12 83 f8 07 0f 87 38 02 00 00 89 c0 48 0f a3 05 1b 80 13 0f <0f> 82 b1 01 00 00 8b 3d e3 b1 13 0f 85 ff 0f 84 25 01 00 00 65 8b
RSP: 0018:ffffc90003eaee48 EFLAGS: 00000297
RAX: 0000000000000001 RBX: ffffffff8e5c11e0 RCX: ffffffff8203a9cc
RDX: ffff88802ddbc880 RSI: ffffffff8203a9e7 RDI: ffffffff8e5c11e0
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000012 R12: ffffffff8203a9e7
R13: ffff88801de9db00 R14: 0000000000000000 R15: ffffc90003eaf060
FS: 0000555565778500(0000) GS:ffff8881247bc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc712f5fd8 CR3: 00000000b0bbf000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
list_lru_count_one+0x14c/0x320 mm/list_lru.c:261
list_lru_shrink_count include/linux/list_lru.h:190 [inline]
super_cache_count+0x174/0x290 fs/super.c:264
do_shrink_slab+0x80/0x1180 mm/shrinker.c:384
shrink_slab_memcg mm/shrinker.c:550 [inline]
shrink_slab+0xa1f/0x12b0 mm/shrinker.c:628
shrink_node_memcgs mm/vmscan.c:6053 [inline]
shrink_node+0x9f4/0x3d50 mm/vmscan.c:6092
shrink_zones mm/vmscan.c:6336 [inline]
do_try_to_free_pages+0x362/0x1920 mm/vmscan.c:6398
try_to_free_mem_cgroup_pages+0x31b/0x790 mm/vmscan.c:6726
try_charge_memcg+0x4d0/0xd50 mm/memcontrol.c:2357
try_charge mm/memcontrol.c:2499 [inline]
charge_memcg+0x8a/0x230 mm/memcontrol.c:4702
mem_cgroup_swapin_charge_folio+0xbb/0x440 mm/memcontrol.c:4788
__read_swap_cache_async+0x43e/0x5a0 mm/swap_state.c:441
swap_cluster_readahead+0x3eb/0x710 mm/swap_state.c:613
swapin_readahead+0x13a/0xd60 mm/swap_state.c:811
do_swap_page+0x635/0x6490 mm/memory.c:4586
handle_pte_fault mm/memory.c:6055 [inline]
__handle_mm_fault+0x1719/0x2a50 mm/memory.c:6195
handle_mm_fault+0x589/0xd10 mm/memory.c:6364
do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7fe80978eb46
Code: fb e8 9e 03 02 00 85 c0 b8 00 00 00 00 48 0f 45 d8 48 89 d8 5b c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 83 ec 28 31 f6 <64> 48 8b 04 25 28 00 00 00 48 89 44 24 18 31 c0 89 f8 48 69 c0 83
RSP: 002b:00007ffd4ccfe2b0 EFLAGS: 00010246
RAX: 0000000000159957 RBX: 00007fe8099b5fa0 RCX: 0000000000159758
RDX: 00000000000001ff RSI: 0000000000000000 RDI: 00000000000003e8
RBP: 00007fe8099b7da0 R08: 0000000000043812 R09: 00007fe80a59b000
R10: 0000000000000001 R11: 001dfc087227a75a R12: 0000000000159bc4
R13: 00007fe8099b6090 R14: ffffffffffffffff R15: 00007ffd4ccfe3f0