GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (3 ticks this GP) idle=351c/1/0x4000000000000000 softirq=46571/46571 fqs=6
rcu: (detected by 0, t=10502 jiffies, g=55817, q=50 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 12868 Comm: syz.6.1660 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:127 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline]
RIP: 0010:kasan_check_range+0x8f/0x290 mm/kasan/generic.c:187
Code: 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 0f 85 cc 01 00 00 <49> ff c3 48 ff c3 75 ee e9 21 01 00 00 44 89 dd 83 e5 07 0f 84 b5
RSP: 0018:ffffc900001f0848 EFLAGS: 00000046
RAX: 0000000000000101 RBX: ffffffffffffffff RCX: ffffffff8167bd44
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90da5618
RBP: 0000000000000008 R08: ffffffff90da561f R09: 1ffffffff21b4ac3
R10: dffffc0000000000 R11: fffffbfff21b4ac3 R12: 0000000000000001
R13: dffffc0000000000 R14: fffffbfff21b4ac4 R15: 1ffffffff21b4ac3
FS: 00007f876c18c6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6b6649c000 CR3: 000000004c3d9000 CR4: 00000000003506e0
Call Trace:
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
hlock_class kernel/locking/lockdep.c:228 [inline]
mark_lock+0x94/0x320 kernel/locking/lockdep.c:4656
mark_usage kernel/locking/lockdep.c:4599 [inline]
__lock_acquire+0xd49/0x7c80 kernel/locking/lockdep.c:5091
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
advance_sched+0xc5/0xc80 net/sched/sch_taprio.c:940
__run_hrtimer kernel/time/hrtimer.c:1755 [inline]
__hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1819
hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:page_ext_next include/linux/page_ext.h:93 [inline]
RIP: 0010:page_table_check_set+0x334/0x6f0 mm/page_table_check.c:132
Code: 89 ee e8 ef e3 9d ff 80 7c 24 0c 00 74 09 83 fd 01 0f 8f ff 00 00 00 e8 2a e0 9d ff 48 b8 00 00 00 00 00 fc ff df 80 3c 03 00 <74> 0c 48 c7 c7 20 69 f1 96 e8 2e 2b f5 ff 4c 03 3d 27 b9 09 15 49
RSP: 0018:ffffc9000d117800 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: 1ffffffff2de2d24 RCX: 0000000000080000
RDX: ffffc9001c409000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: 0000000000000001 R08: ffff88801a41be57 R09: 1ffff110034837ca
R10: dffffc0000000000 R11: ffffed10034837cb R12: 0000000000000000
R13: ffff88801a41be50 R14: 0000000000000000 R15: ffff88801a41be10
page_table_check_ptes_set include/linux/page_table_check.h:74 [inline]
set_ptes include/linux/pgtable.h:238 [inline]
set_pte_range+0x679/0x6a0 mm/memory.c:4406
finish_fault+0x46f/0x970 mm/memory.c:4479
do_read_fault mm/memory.c:4620 [inline]
do_fault mm/memory.c:4753 [inline]
do_pte_missing mm/memory.c:3688 [inline]
handle_pte_fault mm/memory.c:5025 [inline]
__handle_mm_fault mm/memory.c:5166 [inline]
handle_mm_fault+0x38ae/0x4920 mm/memory.c:5331
faultin_page mm/gup.c:868 [inline]
__get_user_pages+0x5ea/0x1470 mm/gup.c:1167
populate_vma_page_range+0x2b6/0x370 mm/gup.c:1593
__mm_populate+0x24c/0x380 mm/gup.c:1696
mm_populate include/linux/mm.h:3328 [inline]
vm_mmap_pgoff+0x2e7/0x400 mm/util.c:561
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f876b38eba9
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:00007f876c18c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f876b5d5fa0 RCX: 00007f876b38eba9
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f876b411e19 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f876b5d6038 R14: 00007f876b5d5fa0 R15: 00007ffd8c4df908
rcu: rcu_preempt kthread starved for 10490 jiffies! g55817 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:27416 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 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:
CPU: 0 PID: 10550 Comm: kworker/u4:10 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xddf/0x1130 kernel/smp.c:855
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 da d6 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 15 d3 0a 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 f9 d2
RSP: 0018:ffffc90005417780 EFLAGS: 00000293
RAX: ffffffff817abd07 RBX: 1ffff110171e82f5 RCX: ffff888078858000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90005417900 R08: ffffffff90da5507 R09: 1ffffffff21b4aa0
R10: dffffc0000000000 R11: fffffbfff21b4aa1 R12: ffff8880b8f417a8
R13: dffffc0000000000 R14: ffff8880b8e3d588 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6b6694f000 CR3: 000000000cb30000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
text_poke_bp_batch+0x318/0x930 arch/x86/kernel/alternative.c:2432
text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
static_key_enable+0x1a/0x20 kernel/jump_label.c:220
toggle_allocation_gate+0xaa/0x250 mm/kfence/core.c:831
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
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