rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (2 GPs behind) idle=0c14/1/0x4000000000000000 softirq=16765/16766 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2935/2:b..l
rcu: (detected by 1, t=10502 jiffies, g=10597, q=421 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 1153 Comm: kworker/u8:7 Not tainted 6.16.0-syzkaller-06588-g759dfc7d04ba #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:86 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x89/0x2c0 mm/kasan/generic.c:189
Code: ff df 4f 8d 1c 17 49 ff c8 4d 89 c1 49 c1 e9 03 48 bb 01 00 00 00 00 fc ff df 4d 8d 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
RSP: 0018:ffffc90000007cd0 EFLAGS: 00000083
RAX: ffffffff81adde01 RBX: dffffc0000000001 RCX: ffffffff81adde77
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fa07af0
RBP: 0000000000000000 R08: ffffffff8fa07af7 R09: 1ffffffff1f40f5e
R10: dffffc0000000000 R11: fffffbfff1f40f5e R12: 0000000000000001
R13: 0000000000000000 R14: fffffbfff1f40f5f R15: 1ffffffff1f40f5e
FS: 0000000000000000(0000) GS:ffff888125c80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000600 CR3: 000000007676a000 CR4: 00000000003526f0
Call Trace:
instrument_atomic_read include/linux/instrumented.h:68 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
cpumask_test_cpu include/linux/cpumask.h:638 [inline]
cpu_online include/linux/cpumask.h:1197 [inline]
trace_hrtimer_start include/trace/events/timer.h:222 [inline]
debug_activate kernel/time/hrtimer.c:485 [inline]
enqueue_hrtimer+0x77/0x3a0 kernel/time/hrtimer.c:1088
__run_hrtimer kernel/time/hrtimer.c:1778 [inline]
__hrtimer_run_queues+0x656/0xc60 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: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:ffffc90003bfe118 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffffffff8fbb0904 RCX: ffffffff8fbb0908
RDX: ffffffff9039caa4 RSI: ffffffff9039caa4 RDI: ffffffff8be309a0
RBP: dffffc0000000000 R08: 0000000000000003 R09: ffffffff8172cd05
R10: ffffc90003bfe238 R11: ffffffff81ac3450 R12: ffffffff9039caa8
R13: ffffffff9039caa9 R14: ffffc90003bfe1e8 R15: ffffffff8fbb0904
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4148 [inline]
slab_alloc_node mm/slub.c:4197 [inline]
kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204
mempool_alloc_noprof+0x1a7/0x510 mm/mempool.c:402
bio_alloc_bioset+0x241/0x1110 block/bio.c:555
bio_alloc_clone block/bio.c:866 [inline]
bio_split+0x110/0x4a0 block/bio.c:1687
bio_submit_split+0x96/0x5e0 block/blk-merge.c:115
__bio_split_to_limits block/blk.h:399 [inline]
blk_mq_submit_bio+0x166a/0x2520 block/blk-mq.c:3164
__submit_bio+0x207/0x5a0 block/blk-core.c:635
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x505/0xb50 block/blk-core.c:751
ext4_io_submit+0xe0/0x150 fs/ext4/page-io.c:404
ext4_do_writepages+0x12d8/0x3f30 fs/ext4/inode.c:2881
ext4_writepages+0x205/0x350 fs/ext4/inode.c:2951
do_writepages+0x32e/0x550 mm/page-writeback.c:2636
__writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680
writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
wb_do_writeback fs/fs-writeback.c:2315 [inline]
wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x70e/0x8a0 kernel/kthread.c:464
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:kworker/u8:9 state:R running task stack:24104 pid:2935 tgid:2935 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7138
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7162
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:414
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline]
__dev_queue_xmit+0x1d79/0x3b50 net/core/dev.c:4740
neigh_output include/net/neighbour.h:547 [inline]
ip6_finish_output2+0x11fe/0x16a0 net/ipv6/ip6_output.c:141
NF_HOOK include/linux/netfilter.h:318 [inline]
ndisc_send_skb+0xb54/0x1440 net/ipv6/ndisc.c:512
ndisc_send_ns+0xcb/0x150 net/ipv6/ndisc.c:670
addrconf_dad_work+0xaae/0x14b0 net/ipv6/addrconf.c:4282
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x70e/0x8a0 kernel/kthread.c:464
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 10502 jiffies! g10597 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:27192 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
__schedule_loop kernel/sched/core.c:7036 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7051
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x70e/0x8a0 kernel/kthread.c:464
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: 49 Comm: kworker/u8:3 Not tainted 6.16.0-syzkaller-06588-g759dfc7d04ba #0 PREEMPT(full)
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:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd38/0x12d0 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 06 70 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 b1 6b 0b 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 95 6b 0b 00 eb e4 44
RSP: 0018:ffffc90000b97660 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff110170c8385 RCX: ffff8880216c9e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000b977e0 R08: ffffffff8fa07af7 R09: 1ffffffff1f40f5e
R10: dffffc0000000000 R11: fffffbfff1f40f5f R12: ffff8880b8641c28
R13: dffffc0000000000 R14: ffff8880b873b180 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125d80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fda4f6e56c0 CR3: 000000000df38000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2901
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245