rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4271/2:b..l
(detected by 0, t=10502 jiffies, g=15237, q=335 ncpus=2)
task:udevd state:R running task stack:23584 pid:4271 ppid:3637 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:cgroup_css+0x49/0x180 kernel/cgroup/cgroup.c:508
Code: 00 00 fc ff df 49 81 c6 94 00 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 00 01 00 00 48 81 c3 98 03 00 00 4d 63 36 10 00 00 00 44 89 f6 e8 6a 56 09 00 49 83 fe 0f 0f 87 fd 00 00
RSP: 0018:ffffc90003d772d0 EFLAGS: 00000282
RAX: 0000000000000000 RBX: ffff8880243383c8 RCX: ffff88802e539dc0
RDX: 0000000000000000 RSI: ffffffff8dff3b98 RDI: ffff888024338030
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff2119049
R10: fffffbfff2119049 R11: 1ffffffff2119048 R12: ffff888024570000
R13: dffffc0000000000 R14: 0000000000000004 R15: dffffc0000000000
cgroup_get_e_css+0xd0/0x260 kernel/cgroup/cgroup.c:621
loop_queue_rq+0x1e2/0xac0 drivers/block/loop.c:1868
__blk_mq_issue_directly block/blk-mq.c:2631 [inline]
__blk_mq_try_issue_directly+0x4ab/0x7a0 block/blk-mq.c:2684
blk_mq_request_issue_directly block/blk-mq.c:2718 [inline]
blk_mq_plug_issue_direct+0x233/0x620 block/blk-mq.c:2738
blk_mq_flush_plug_list+0x7e7/0xd40 block/blk-mq.c:2838
__blk_flush_plug+0x3c6/0x440 block/blk-core.c:1179
blk_finish_plug+0x59/0x80 block/blk-core.c:1203
read_pages+0x646/0x840 mm/readahead.c:184
page_cache_ra_unbounded+0x690/0x770 mm/readahead.c:270
do_page_cache_ra mm/readahead.c:300 [inline]
force_page_cache_ra mm/readahead.c:331 [inline]
page_cache_sync_ra+0x3d7/0x490 mm/readahead.c:713
page_cache_sync_readahead include/linux/pagemap.h:1250 [inline]
filemap_get_pages mm/filemap.c:2665 [inline]
filemap_read+0x5ff/0x2f80 mm/filemap.c:2759
blkdev_read_iter+0x42d/0x570 block/fops.c:668
call_read_iter include/linux/fs.h:2259 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x434/0x920 fs/read_write.c:470
ksys_read+0x143/0x240 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fab489cd407
RSP: 002b:00007fff06aaf610 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fab48941880 RCX: 00007fab489cd407
RDX: 0000000000000200 RSI: 00007fab4839a000 RDI: 0000000000000009
RBP: 000055e483ec2050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000020000 R14: 000055e483ede538 R15: 00007fab48be639c
rcu: rcu_preempt kthread starved for 8004 jiffies! g15237 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26432 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x7b/0x290 mm/kasan/generic.c:189
Code: 5c 37 ff 48 c1 eb 03 4e 8d 14 3b 4d 89 d6 4d 29 ce 49 83 fe 10 7f 26 4d 85 f6 0f 84 39 01 00 00 48 f7 d3 4c 01 db 41 80 39 00 <0f> 85 c1 01 00 00 49 ff c1 48 ff c3 75 ee e9 1c 01 00 00 44 89 cb
RSP: 0018:ffffc90000157b80 EFLAGS: 00000246
RAX: ffffffff8a1a4601 RBX: fffffffffffffff6 RCX: ffffffff8a1a4670
RDX: 0000000000000001 RSI: 0000000000000050 RDI: ffffc90000157be0
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffff5200002af7c
R10: fffff5200002af86 R11: 1ffff9200002af7c R12: 1ffff9200002af78
R13: ffffffff8c930b80 R14: 000000000000000a R15: dffffc0000000001
memset+0x1e/0x40 mm/kasan/shadow.c:44
schedule_timeout+0xb0/0x280 kernel/time/timer.c:2131
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742
Code: 48 89 df e8 a7 b3 b6 f7 e9 4c ff ff ff e8 9d 0e f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d c7 40 4c 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffffff8c607d88 EFLAGS: 000002c6
RAX: f47ad3d5a0407500 RBX: ffffffff8a1a6267 RCX: f47ad3d5a0407500
RDX: 0000000000000001 RSI: ffffffff8a6c0600 RDI: ffffffff8abef920
RBP: ffffffff8c607ec0 R08: dffffc0000000000 R09: ffffed10171c6afa
R10: ffffed10171c6afa R11: 1ffff110171c6af9 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff8c6bc740 R15: 1ffffffff1bfe206
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fab48394000 CR3: 000000005e502000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
default_idle_call+0x84/0xc0 kernel/sched/idle.c:109
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x1fc/0x570 kernel/sched/idle.c:303
cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401
rest_init+0x2dc/0x300 init/main.c:745
arch_call_rest_init+0xa/0xa init/main.c:905
start_kernel+0x490/0x539 init/main.c:1152
secondary_startup_64_no_verify+0xcf/0xdb