rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P109/1:b..l P394/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=9705, q=354 ncpus=2)
task:kworker/u8:6 state:R running task stack:21912 pid:394 tgid:394 ppid:2 task_flags:0x24248060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__asan_memset+0x31/0x50 mm/kasan/shadow.c:87
Code: 53 48 89 d3 89 f5 49 89 fe 48 8b 4c 24 18 48 89 d6 ba 01 00 00 00 e8 7e e4 ff ff 84 c0 74 11 4c 89 f7 89 ee 48 89 da 5b 41 5e <5d> e9 e9 d7 33 09 31 c0 5b 41 5e 5d e9 99 2f e8 fe cc 66 66 66 66
RSP: 0018:ffffc900031a6028 EFLAGS: 00000202
RAX: ffffc900031a6c01 RBX: ffffc900031a6140 RCX: ffffffff81744d8e
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc900031a6158
RBP: 0000000000000000 R08: ffffc900031a6167 R09: 1ffff92000634c2c
R10: dffffc0000000000 R11: fffff52000634c2d R12: ffffc900031a6158
R13: 1ffff92000634c23 R14: ffffc900031a6108 R15: ffffc900031a6150
unwind_next_frame+0xeae/0x23d0 arch/x86/kernel/unwind_orc.c:607
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:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:339 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5270
mempool_alloc_noprof+0x1c9/0x2f0 mm/mempool.c:567
bio_alloc_bioset+0x28d/0x12d0 block/bio.c:561
bio_alloc_clone block/bio.c:873 [inline]
bio_split+0x110/0x4a0 block/bio.c:1711
bio_submit_split_bioset+0x3b/0x9a0 block/blk-merge.c:122
bio_submit_split block/blk-merge.c:152 [inline]
bio_split_rw+0x335/0x510 block/blk-merge.c:406
__bio_split_to_limits block/blk.h:402 [inline]
blk_mq_submit_bio+0x16ca/0x26b0 block/blk-mq.c:3184
__submit_bio+0x207/0x5a0 block/blk-core.c:637
__submit_bio_noacct_mq block/blk-core.c:724 [inline]
submit_bio_noacct_nocheck+0x377/0xa30 block/blk-core.c:755
ext4_io_submit fs/ext4/page-io.c:404 [inline]
io_submit_add_bh fs/ext4/page-io.c:445 [inline]
ext4_bio_write_folio+0x1087/0x1f20 fs/ext4/page-io.c:589
mpage_map_and_submit_buffers fs/ext4/inode.c:2330 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2520 [inline]
ext4_do_writepages+0x1fe9/0x4500 fs/ext4/inode.c:2932
ext4_writepages+0x203/0x350 fs/ext4/inode.c:3026
do_writepages+0x32e/0x550 mm/page-writeback.c:2598
__writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
writeback_sb_inodes+0x93a/0x1870 fs/fs-writeback.c:2030
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218
wb_check_old_data_flush fs/fs-writeback.c:2322 [inline]
wb_do_writeback fs/fs-writeback.c:2375 [inline]
wb_workfn+0xad2/0xed0 fs/fs-writeback.c:2403
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
task:kworker/1:2 state:R running task stack:25824 pid:109 tgid:109 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient gc_worker
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7140
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:752
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3b0 kernel/locking/lockdep.c:5879
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:897 [inline]
gc_worker+0xba6/0x1380 net/netfilter/nf_conntrack_core.c:1617
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: rcu_preempt kthread starved for 10603 jiffies! g9705 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:27240 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
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+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 5e 83 b4 f5 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 93 90 0c 00 f3 0f 1e fa fb f4 33 83 b4 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 3f82518d0c66f600 RBX: ffffffff81978fda RCX: 3f82518d0c66f600
RDX: 0000000000000001 RSI: ffffffff8d7925c0 RDI: ffffffff8bc08360
RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db
R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f822070
R13: 1ffff1100385fb70 R14: 0000000000000001 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125f35000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3ec065a0d0 CR3: 0000000072fa1000 CR4: 0000000000350ef0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1ea/0x520 kernel/sched/idle.c:332
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x147