rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=d324/1/0x4000000000000000 softirq=26729/26741 fqs=0
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7286/1:b..l P8589/3:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=18853, q=315 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8588 Comm: syz.2.820 Not tainted 6.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:timerqueue_add+0x1c2/0x330 lib/timerqueue.c:41
Code: 44 89 f6 49 89 2f e8 1d 5d 66 f6 45 84 f6 0f 85 a9 00 00 00 e8 6f 62 66 f6 48 8b 34 24 48 89 ef e8 13 8f ff ff e8 5e 62 66 f6 <44> 89 f0 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc
RSP: 0018:ffffc90000007df0 EFLAGS: 00000046
RAX: 0000000080010001 RBX: 0000000000000000 RCX: ffffffff8b537c18
RDX: ffff88807ca74880 RSI: ffffffff8b537d92 RDI: ffff888025107340
RBP: ffff888025107340 R08: 0000000000000006 R09: ffff888025107340
R10: ffff888025107340 R11: 0000000000000001 R12: ffff888025107340
R13: ffff8880b862c880 R14: ffff8880b862c601 R15: ffffffff896a7a20
FS:  00007fd631ff66c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f115c9a7bac CR3: 000000005c078000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __run_hrtimer kernel/time/hrtimer.c:1818 [inline]
 __hrtimer_run_queues+0x903/0xae0 kernel/time/hrtimer.c:1865
 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__might_fault mm/memory.c:6851 [inline]
RIP: 0010:__might_fault+0xd8/0x190 mm/memory.c:6844
Code: 83 bb 58 05 00 00 00 74 b0 e8 04 16 b7 ff 48 b8 00 00 00 00 00 fc ff df 65 48 8b 1d 42 0f 01 7e 48 8d bb 58 05 00 00 48 89 fa <48> c1 ea 03 48 8d 2d 00 00 00 00 80 3c 02 00 0f 85 88 00 00 00 48
RSP: 0018:ffffc9000bd6fa38 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffff88807ca74880 RCX: ffffc9000e286000
RDX: ffff88807ca74dd8 RSI: ffffffff8202c9ec RDI: ffff88807ca74dd8
RBP: 00000000000000a2 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffc9000bd6faa8 R14: ffffc9000bd6fb90 R15: ffffc9000bd6faa8
 _inline_copy_from_user include/linux/uaccess.h:162 [inline]
 _copy_from_user+0x29/0xd0 lib/usercopy.c:18
 copy_from_user include/linux/uaccess.h:212 [inline]
 copy_msghdr_from_user+0x99/0x160 net/socket.c:2503
 recvmsg_copy_msghdr net/socket.c:2759 [inline]
 ___sys_recvmsg+0xdc/0x1a0 net/socket.c:2831
 do_recvmmsg+0x2f8/0x740 net/socket.c:2930
 __sys_recvmmsg net/socket.c:3004 [inline]
 __do_sys_recvmmsg net/socket.c:3027 [inline]
 __se_sys_recvmmsg net/socket.c:3020 [inline]
 __x64_sys_recvmmsg+0x239/0x290 net/socket.c:3020
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd63418d169
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:00007fd631ff6038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fd6343a6080 RCX: 00007fd63418d169
RDX: 0000000000010106 RSI: 00004000000000c0 RDI: 0000000000000003
RBP: 00007fd63420e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd6343a6080 R15: 00007fffd8fce8b8
 </TASK>
task:syz.4.821       state:R  running task     stack:25024 pid:8589  tgid:8587  ppid:5827   task_flags:0x400040 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7087
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5928
Code: 00 00 b8 ff ff ff ff 65 0f c1 05 3c 55 ab 74 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 45 31 ed eb
RSP: 0018:ffffc9000be5ea60 EFLAGS: 00000296
RAX: 0000000000000046 RBX: ffff888031f60b18 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8b6cef80 RDI: ffffffff8bd35640
RBP: ffffffff8e1bcc80 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000003 R12: ffff888031f60000
R13: 0000000000000001 R14: 00000000ffffffff R15: 0000000000000001
 __find_rr_leaf+0x36d/0xe00 net/ipv6/route.c:800
 find_rr_leaf net/ipv6/route.c:856 [inline]
 rt6_select net/ipv6/route.c:900 [inline]
 fib6_table_lookup+0x57e/0xa30 net/ipv6/route.c:2195
 ip6_pol_route+0x1cd/0x1120 net/ipv6/route.c:2231
 pol_lookup_func include/net/ip6_fib.h:616 [inline]
 fib6_rule_lookup+0x386/0x720 net/ipv6/fib6_rules.c:124
 ip6_route_output_flags_noref net/ipv6/route.c:2639 [inline]
 ip6_route_output_flags+0x1d0/0x640 net/ipv6/route.c:2651
 ip6_dst_lookup_tail.constprop.0+0x1159/0x2150 net/ipv6/ip6_output.c:1156
 ip6_dst_lookup_flow+0x99/0x1d0 net/ipv6/ip6_output.c:1259
 sctp_v6_get_dst+0x14d7/0x2050 net/sctp/ipv6.c:384
 sctp_transport_route+0x12e/0x350 net/sctp/transport.c:455
 sctp_packet_config+0x808/0xf40 net/sctp/output.c:103
 sctp_packet_singleton+0x16f/0x370 net/sctp/outqueue.c:777
 sctp_outq_flush_ctrl net/sctp/outqueue.c:914 [inline]
 sctp_outq_flush+0x54d/0x3380 net/sctp/outqueue.c:1212
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1818 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline]
 sctp_do_sm+0x179c/0x5c90 net/sctp/sm_sideeffect.c:1169
 sctp_primitive_ASSOCIATE+0x9c/0xd0 net/sctp/primitive.c:73
 sctp_sendmsg_to_asoc+0xa4d/0x1ad0 net/sctp/socket.c:1841
 sctp_sendmsg+0xf0a/0x1eb0 net/sctp/socket.c:2031
 inet_sendmsg+0x119/0x140 net/ipv4/af_inet.c:851
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:733 [inline]
 __sys_sendto+0x42a/0x4f0 net/socket.c:2187
 __do_sys_sendto net/socket.c:2194 [inline]
 __se_sys_sendto net/socket.c:2190 [inline]
 __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2190
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f115c78d169
RSP: 002b:00007f115d58b038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f115c9a5fa0 RCX: 00007f115c78d169
RDX: 0000000000000001 RSI: 0000400000000200 RDI: 0000000000000003
RBP: 00007f115c80e2a0 R08: 0000400000000040 R09: 000000000000001c
R10: 0000000020040840 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f115c9a5fa0 R15: 00007ffc01a692f8
 </TASK>
task:syz-executor    state:R  running task     stack:23600 pid:7286  tgid:7286  ppid:7258   task_flags:0x400140 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6944
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 copy_pte_range mm/memory.c:1201 [inline]
 copy_pmd_range mm/memory.c:1262 [inline]
 copy_pud_range mm/memory.c:1299 [inline]
 copy_p4d_range mm/memory.c:1323 [inline]
 copy_page_range+0x1e7f/0x5690 mm/memory.c:1421
 dup_mmap kernel/fork.c:748 [inline]
 dup_mm kernel/fork.c:1700 [inline]
 copy_mm kernel/fork.c:1752 [inline]
 copy_process+0x7ccb/0x8c50 kernel/fork.c:2403
 kernel_clone+0xfd/0x960 kernel/fork.c:2815
 __do_sys_clone+0xcf/0x120 kernel/fork.c:2958
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f67e47839d3
RSP: 002b:00007ffc3d88f978 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f67e47839d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055558c6247d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 0000000000039233 R15: 00007ffc3d88fb10
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g18853 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:28344 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 5818 Comm: syz-executor Not tainted 6.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:write_comp_data+0x0/0x90 kernel/kcov.c:240
Code: 48 8b 05 33 00 4a 7e 48 8b 80 20 16 00 00 c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <49> 89 d2 49 89 f8 49 89 f1 65 48 8b 15 ff ff 49 7e 65 8b 05 00 00
RSP: 0018:ffffc900032e78f0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffff8880b8646a00 RCX: ffffffff81add19a
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffed10170c8d41
R13: 0000000000000001 R14: ffff8880b873fe80 R15: ffff8880b8646a08
FS:  00005555808b4500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f67e54d56c0 CR3: 0000000034d22000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 csd_lock_wait kernel/smp.c:340 [inline]
 smp_call_function_many_cond+0x4ea/0x12c0 kernel/smp.c:885
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:966 [inline]
 flush_tlb_mm_range+0x271/0x4a0 arch/x86/mm/tlb.c:1054
 dup_mmap kernel/fork.c:787 [inline]
 dup_mm kernel/fork.c:1700 [inline]
 copy_mm kernel/fork.c:1752 [inline]
 copy_process+0x70fb/0x8c50 kernel/fork.c:2403
 kernel_clone+0xfd/0x960 kernel/fork.c:2815
 __do_sys_clone+0xcf/0x120 kernel/fork.c:2958
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f04b29839d3
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 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 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffd220d5858 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f04b29839d3
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 00005555808b47d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 00000000000390d1 R15: 00007ffd220d59f0
 </TASK>