rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=18fc/1/0x4000000000000000 softirq=70559/70559 fqs=3
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12172/1:b..l..
rcu: (detected by 1, t=10502 jiffies, g=82817, q=2371 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12178 Comm: syz.2.1108 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
RIP: 0010:__lock_acquire+0x768/0x2de0 kernel/locking/lockdep.c:5258
Code: 08 00 00 00 e8 a9 46 00 00 45 31 f6 85 c0 0f 84 7c 0d 00 00 83 3d e7 00 48 1a 00 75 13 48 63 44 24 20 48 0f a3 05 f8 70 44 14 <0f> 83 9f 1e 00 00 48 8b 44 24 08 48 8b 98 98 0b 00 00 48 83 7c 24
RSP: 0018:ffffc90000007b00 EFLAGS: 00000047
RAX: 00000000000008e4 RBX: 0000000000000001 RCX: ffffffff9590abb0
RDX: 0000000000000008 RSI: ffff888063aaab18 RDI: ffff888063aa9f40
RBP: ffff888063aaab18 R08: ffffffff8a0ed352 R09: 0000000000000001
R10: dffffc0000000000 R11: ffffffff8a0ed290 R12: ffffffffffffff03
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007fca530af6c0(0000) GS:ffff8881233f0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000188000 CR3: 0000000060da8000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
__raw_spin_lock include/linux/spinlock_api_smp.h:190 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:173
spin_lock include/linux/spinlock.h:347 [inline]
advance_sched+0xc2/0xc80 net/sched/sch_taprio.c:943
__run_hrtimer kernel/time/hrtimer.c:2079 [inline]
__hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2136
hrtimer_interrupt+0x4cd/0xaa0 kernel/time/hrtimer.c:2255
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1079
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1073 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1073
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:221
Code: f7 e8 dd a8 96 f5 f7 c3 00 02 00 00 74 05 e8 70 4c c3 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 14 9d 87 f5 65 48 8b 05 4c c1 d4 08 48 85 c0 74 18 5b 41 5e e9
RSP: 0018:ffffc900026cfc08 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000246 RCX: 8000000000000001
RDX: 0000000000000007 RSI: ffffffff8e6af44b RDI: 0000000000000001
RBP: ffffc900026cfd30 R08: ffffffff91be54bf R09: 1ffffffff237ca97
R10: dffffc0000000000 R11: fffffbfff237ca98 R12: 000000866d567400
R13: dffffc0000000000 R14: ffff8880b8228600 R15: 0000000000000180
class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:596 [inline]
clock_was_set+0x6b4/0x890 kernel/time/hrtimer.c:1001
do_settimeofday64+0x34e/0x5a0 kernel/time/timekeeping.c:1733
__do_sys_clock_settime kernel/time/posix-timers.c:1152 [inline]
__se_sys_clock_settime kernel/time/posix-timers.c:1136 [inline]
__x64_sys_clock_settime+0x253/0x2a0 kernel/time/posix-timers.c:1136
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x00007fca5219fb19
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fca530af028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3
RAX: ffffffffffffffda RBX: 00007fca52425fa0 RCX: 00007fca5219fb19
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000000
RBP: 00007fca52237b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fca52426038 R14: 00007fca52425fa0 R15: 00007ffda859fe88
task:syz.0.1107 state:R running task stack:24168 pid:12172 tgid:12169 ppid:11375 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5830 kernel/sched/core.c:7382
preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7662
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:543 [inline]
irqentry_exit+0x14f/0x9b0 kernel/entry/common.c:154
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5947
Code: ff ff ff e8 90 36 67 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 32 c0 3e 13 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 cf 49 6a 0a cc 48 8d 3d 27 4f 1d
RSP: 0018:ffffc9000329f168 EFLAGS: 00000282
RAX: c342e32bbd80d800 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000fd2e0abe RSI: ffffffff8e93c1df RDI: ffffffff8c8eba80
RBP: ffff888055aaddc0 R08: ffffffff822db969 R09: 0000000000000000
R10: ffffc9000329f38c R11: fffff52000653e7a R12: ffffffff9015a560
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
__pte_offset_map+0x45/0x240 mm/pgtable-generic.c:302
pte_offset_map_rw_nolock+0x3b/0x160 mm/pgtable-generic.c:342
handle_pte_fault mm/memory.c:6617 [inline]
__handle_mm_fault mm/memory.c:6784 [inline]
handle_mm_fault+0x105a/0x2f80 mm/memory.c:6951
do_user_addr_fault+0x7f6/0x1480 arch/x86/mm/fault.c:1394
handle_page_fault arch/x86/mm/fault.c:1483 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0010:rep_movs_alternative+0x4a/0xa0 arch/x86/lib/copy_user_64.S:74
Code: 7d 04 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 73 e8 eb c5 a4 c3 cc cc cc cc 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48
RSP: 0018:ffffc9000329f5f8 EFLAGS: 00050206
RAX: 00007ffffffff001 RBX: ffff888079d4f000 RCX: 0000000000000c40
RDX: 0000000000000001 RSI: 0000200000188000 RDI: ffff888079d4f3c0
RBP: ffffc9000329f760 R08: ffff888079d4ffff R09: 1ffff1100f3a9fff
R10: dffffc0000000000 R11: ffffed100f3aa000 R12: ffffc9000329fe18
R13: 0000200000187c40 R14: 0000000000001000 R15: 1ffff92000653fc3
copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline]
copy_from_user_iter lib/iov_iter.c:67 [inline]
iterate_ubuf include/linux/iov_iter.h:30 [inline]
iterate_and_advance2 include/linux/iov_iter.h:302 [inline]
iterate_and_advance include/linux/iov_iter.h:332 [inline]
__copy_from_iter lib/iov_iter.c:261 [inline]
_copy_from_iter+0x21b/0x1680 lib/iov_iter.c:272
copy_page_from_iter+0x219/0x2d0 lib/iov_iter.c:434
skb_copy_datagram_from_iter+0x2f4/0x720 net/core/datagram.c:580
unix_stream_sendmsg+0x5d4/0xe00 net/unix/af_unix.c:2478
sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
__sock_sendmsg net/socket.c:818 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2715
___sys_sendmsg+0x2a6/0x360 net/socket.c:2769
__sys_sendmsg net/socket.c:2801 [inline]
__do_sys_sendmsg net/socket.c:2806 [inline]
__se_sys_sendmsg net/socket.c:2804 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x00007f6c7a79fb19
RSP: 002b:00007f6c7b6d3028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6c7aa25fa0 RCX: 00007f6c7a79fb19
RDX: 0000000000000003 RSI: 00002000000002c0 RDI: 0000000000000003
RBP: 00007f6c7a837b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6c7aa26038 R14: 00007f6c7aa25fa0 R15: 00007ffc4b7c8878
rcu: rcu_preempt kthread starved for 10496 jiffies! g82817 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27696 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5830 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x1230 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9c/0x340 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
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: 5300 Comm: dhcpcd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
RIP: 0010:csd_lock_wait kernel/smp.c:389 [inline]
RIP: 0010:csd_lock kernel/smp.c:422 [inline]
RIP: 0010:smp_call_function_many_cond+0x61e/0x1500 kernel/smp.c:970
Code: b6 04 04 84 c0 0f 85 d5 03 00 00 44 8b 3b 44 89 fe 83 e6 01 31 ff e8 f1 79 0c 00 41 83 e7 01 75 07 e8 d6 74 0c 00 eb 3f f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 75 0f f7 03 01
RSP: 0018:ffffc9000354f420 EFLAGS: 00000293
RAX: ffffffff81bcbf6e RBX: ffff8880b8244328 RCX: ffff88802f349f40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000354f570 R08: ffff88802f34b4df R09: 1ffff11005e6969b
R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff11017048865
R13: 0000000000000000 R14: ffff8880b8244320 R15: 0000000000000001
FS: 00007f8bc73df780(0000) GS:ffff8881234f0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e0e322b5f8 CR3: 000000007fcbc000 CR4: 00000000003526f0
Call Trace:
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x910/0x10b0 arch/x86/mm/tlb.c:1435
dup_mmap+0x1617/0x1c80 mm/mmap.c:1878
dup_mm kernel/fork.c:1551 [inline]
copy_mm+0x2ae/0x640 kernel/fork.c:1604
copy_process+0x1ecc/0x4510 kernel/fork.c:2330
kernel_clone+0x2d7/0x940 kernel/fork.c:2800
__do_sys_clone kernel/fork.c:2942 [inline]
__se_sys_clone kernel/fork.c:2926 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2926
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x16a/0x530 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x00007f8bc74b3636
Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffd05859bb0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffd05859bb8 RCX: 00007f8bc74b3636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffd0587a100 R08: 0000000000000000 R09: 0000000000000001
R10: 00007f8bc73dfa50 R11: 0000000000000246 R12: 00007ffd05859cf0
R13: 0000000000000000 R14: 0000000000000000 R15: 000055c8b287aac0