rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5881/1:b..l P11909/1:b..l
rcu: (detected by 1, t=10504 jiffies, g=46033, q=281 ncpus=2)
task:modprobe state:R running task stack:23992 pid:11909 tgid:11909 ppid:5995 task_flags:0x40000c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169
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+0x3f/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+0x3a79/0x4370 mm/memory.c:1889
unmap_single_vma mm/memory.c:1932 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:1976
exit_mmap+0x248/0xb50 mm/mmap.c:1280
__mmput+0x118/0x430 kernel/fork.c:1129
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 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+0x3f/0x40 kernel/exit.c:1111
x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa17b10c6c5
RSP: 002b:00007ffeafb3f9f8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fa17b20dfe8 RCX: 00007fa17b10c6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001
RBP: 0000000000000001 R08: 00007ffeafb3f988 R09: 0000000000000000
R10: 00007ffeafb3f820 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fa17b20c680 R15: 00007fa17b20e000
task:udevd state:R running task stack:22472 pid:5881 tgid:5881 ppid:5227 task_flags:0x20440140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
_raw_spin_unlock_irq+0x45/0x50 kernel/locking/spinlock.c:202
spin_unlock_irq include/linux/spinlock.h:401 [inline]
loop_queue_work drivers/block/loop.c:863 [inline]
loop_queue_rq+0x9f8/0xb00 drivers/block/loop.c:1887
__blk_mq_issue_directly block/blk-mq.c:2695 [inline]
blk_mq_request_issue_directly+0x3c1/0x710 block/blk-mq.c:2782
blk_mq_issue_direct+0x2a0/0x660 block/blk-mq.c:2803
blk_mq_dispatch_queue_requests+0x6fe/0x800 block/blk-mq.c:2878
blk_mq_flush_plug_list+0x432/0x550 block/blk-mq.c:2961
__blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
blk_finish_plug+0x5e/0x90 block/blk-core.c:1247
read_pages+0x3b2/0x580 mm/readahead.c:173
page_cache_ra_unbounded+0x6b0/0x7b0 mm/readahead.c:297
do_page_cache_ra mm/readahead.c:327 [inline]
force_page_cache_ra mm/readahead.c:356 [inline]
page_cache_sync_ra+0x3b9/0xb10 mm/readahead.c:572
filemap_get_pages+0x43c/0x1ea0 mm/filemap.c:2603
filemap_read+0x3f6/0x11a0 mm/filemap.c:2712
blkdev_read_iter+0x30a/0x440 block/fops.c:852
new_sync_read fs/read_write.c:491 [inline]
vfs_read+0x55a/0xa30 fs/read_write.c:572
ksys_read+0x145/0x250 fs/read_write.c:715
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb5842a7407
RSP: 002b:00007ffc51aa2ec0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fb584a1f880 RCX: 00007fb5842a7407
RDX: 0000000000000200 RSI: 00007fb584a1e000 RDI: 0000000000000009
RBP: 000055573ec0d050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 000055573ec156f8 R15: 00007fb584b4639c
rcu: rcu_preempt kthread timer wakeup didn't happen for 10500 jiffies! g46033 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=50792
rcu: rcu_preempt kthread starved for 10501 jiffies! g46033 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:26496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
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+0x439/0x7d0 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 11915 Comm: syz.2.1427 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:227 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:239 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:646 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:1205 [inline]
RIP: 0010:trace_hrtimer_start include/trace/events/timer.h:222 [inline]
RIP: 0010:debug_activate kernel/time/hrtimer.c:485 [inline]
RIP: 0010:enqueue_hrtimer+0x81/0x3a0 kernel/time/hrtimer.c:1088
Code: 00 00 e8 22 ca 11 00 45 89 fd 41 c1 ef 06 4a 8d 3c fd 30 a8 a3 8f be 08 00 00 00 e8 e9 49 75 00 31 f6 4c 0f a3 2d 9f c4 f5 0d <40> 0f 92 c5 40 0f 92 c6 bf 02 00 00 00 e8 ed cc 11 00 40 84 ed 74
RSP: 0018:ffffc90000007d08 EFLAGS: 00000047
RAX: ffffffff81ade301 RBX: ffff88807c227340 RCX: ffffffff81ade387
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8fa3a830
RBP: 0000000000000000 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff8880b8627c00 R15: 0000000000000000
FS: 00007f68344826c0(0000) GS:ffff888125c12000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa17afade9c CR3: 00000000781bb000 CR4: 0000000000350ef0
Call Trace:
__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+0x10b/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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 5b 68 4a f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e3 0e 13 f6 65 8b 05 6c f1 23 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc900156c6e00 EFLAGS: 00000206
RAX: a1f6875825097000 RBX: 0000000000000216 RCX: a1f6875825097000
RDX: 0000000000000002 RSI: ffffffff8d9ba32d RDI: 0000000000000001
RBP: ffffc900156c6e90 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88807c2272e8 R15: 1ffff92002ad8dc0
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
taprio_change+0x302c/0x3c40 net/sched/sch_taprio.c:1985
taprio_init+0x959/0xbd0 net/sched/sch_taprio.c:2125
qdisc_create+0x7ac/0xea0 net/sched/sch_api.c:1319
__tc_modify_qdisc net/sched/sch_api.c:1748 [inline]
tc_modify_qdisc+0x1538/0x20e0 net/sched/sch_api.c:1812
rtnetlink_rcv_msg+0x77c/0xb70 net/core/rtnetlink.c:6955
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:729
____sys_sendmsg+0x505/0x830 net/socket.c:2614
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
__sys_sendmsg net/socket.c:2700 [inline]
__do_sys_sendmsg net/socket.c:2705 [inline]
__se_sys_sendmsg net/socket.c:2703 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f683358eec9
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:00007f6834482038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f68337e5fa0 RCX: 00007f683358eec9
RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000004
RBP: 00007f6833611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f68337e6038 R14: 00007f68337e5fa0 R15: 00007fffb1ed16d8