syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P16375/1:b..l P16381/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=84121, q=238 ncpus=2)
task:modprobe        state:R  running task     stack:24104 pid:16381 tgid:16381 ppid:12883  task_flags:0x400000 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5392 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6781
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7104
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:218 [inline]
RIP: 0010:unwind_next_frame+0x223/0x2390 arch/x86/kernel/unwind_orc.c:494
Code: 86 65 18 00 00 44 89 f8 4c 8d 2c 85 f4 bb d9 90 4c 89 e8 48 c1 e8 03 0f b6 04 28 84 c0 48 89 eb 0f 85 1c 1c 00 00 45 8b 6d 00 <44> 89 f8 ff c0 48 8d 2c 85 f4 bb d9 90 48 89 e8 48 c1 e8 03 0f b6
RSP: 0018:ffffc9000b866ef8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 3771518cd2b55a00
RDX: 00000000000a6144 RSI: ffffffff8be1a060 RDI: ffffffff8be1a020
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff81728e15
R10: ffffc9000b867018 R11: ffffffff81ace490 R12: ffffffff8216acb0
R13: 00000000000387d8 R14: ffffc9000b866fc8 R15: 00000000000116ac
 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:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4147 [inline]
 slab_alloc_node mm/slub.c:4196 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4203
 mt_alloc_one lib/maple_tree.c:176 [inline]
 mas_alloc_nodes+0x2e9/0x8e0 lib/maple_tree.c:1249
 mas_node_count_gfp lib/maple_tree.c:1331 [inline]
 mas_preallocate+0x39e/0x6b0 lib/maple_tree.c:5532
 vma_iter_prealloc mm/vma.h:409 [inline]
 commit_merge+0x1f1/0x6e0 mm/vma.c:737
 vma_expand+0x41c/0x7d0 mm/vma.c:1154
 vma_merge_new_range+0x5dc/0x7a0 mm/vma.c:1092
 __mmap_region mm/vma.c:2610 [inline]
 mmap_region+0xc4f/0x1f30 mm/vma.c:2685
 do_mmap+0xc45/0x10d0 mm/mmap.c:561
 vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579
 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: 0033:0x7f80a952f242
RSP: 002b:00007fff7d2c69a8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f80a9205000 RCX: 00007f80a952f242
RDX: 0000000000000003 RSI: 0000000000000088 RDI: 00007f80a9205000
RBP: 0000000000000032 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000032 R11: 0000000000000206 R12: 00007fff7d2c6a68
R13: 00007f80a92060c0 R14: 00007fff7d2c6de0 R15: 00007f80a9205000
 </TASK>
task:syz.8.3007      state:R  running task     stack:22416 pid:16375 tgid:16369 ppid:12353  task_flags:0x400140 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5392 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6781
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7104
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:queue_work_on+0x1f7/0x270 kernel/workqueue.c:2397
Code: 4d 85 ff 75 16 e8 f9 92 35 00 eb 15 e8 f2 92 35 00 e8 1d d2 d2 09 4d 85 ff 74 ea e8 e3 92 35 00 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 04 2e 00 00 00 00 66 43 c7 44 2e 09 00 00 43 c6 44 2e 0b 00
RSP: 0000:ffffc9000431e240 EFLAGS: 00000287
RAX: ffffffff818ab6fd RBX: ffff888145b39301 RCX: 0000000000080000
RDX: ffffc90023bf1000 RSI: 0000000000007b58 RDI: 0000000000007b59
RBP: ffffc9000431e338 R08: ffffffff8f9fb6f7 R09: 1ffffffff1f3f6de
R10: dffffc0000000000 R11: fffffbfff1f3f6df R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff92000863c50 R15: 0000000000000200
 queue_work include/linux/workqueue.h:662 [inline]
 schedule_work include/linux/workqueue.h:723 [inline]
 nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:-1 [inline]
 nsim_fib_event_nb+0xe0d/0x1080 drivers/net/netdevsim/fib.c:1043
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 atomic_notifier_call_chain+0xda/0x180 kernel/notifier.c:223
 call_fib_notifiers+0x31/0x60 net/core/fib_notifier.c:35
 call_fib_entry_notifiers net/ipv4/fib_trie.c:107 [inline]
 fib_notify_alias_delete net/ipv4/fib_trie.c:1683 [inline]
 fib_table_delete+0xc65/0xf80 net/ipv4/fib_trie.c:1739
 fib_magic+0x2e4/0x390 net/ipv4/fib_frontend.c:1135
 fib_del_ifaddr+0x28b/0x1480 net/ipv4/fib_frontend.c:1246
 fib_inetaddr_event+0xbb/0x190 net/ipv4/fib_frontend.c:1477
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
 __inet_del_ifa+0x87d/0x1040 net/ipv4/devinet.c:451
 inet_del_ifa net/ipv4/devinet.c:488 [inline]
 inetdev_destroy net/ipv4/devinet.c:328 [inline]
 inetdev_event+0x632/0x15b0 net/ipv4/devinet.c:1656
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_mtu net/core/dev.c:2305 [inline]
 netif_set_mtu_ext+0x438/0x620 net/core/dev.c:9591
 do_setlink+0x91a/0x41c0 net/core/rtnetlink.c:3104
 rtnl_setlink+0x604/0x900 net/core/rtnetlink.c:3455
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6944
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:727
 sock_write_iter+0x258/0x330 net/socket.c:1131
 do_iter_readv_writev+0x518/0x6e0 fs/read_write.c:-1
 vfs_writev+0x31a/0x960 fs/read_write.c:1057
 do_writev+0x14d/0x2d0 fs/read_write.c:1103
 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: 0033:0x7f17b2b8e969
RSP: 002b:00007f17b3a93038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f17b2db6160 RCX: 00007f17b2b8e969
RDX: 0000000000000001 RSI: 00002000000003c0 RDI: 0000000000000008
RBP: 00007f17b2c10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f17b2db6160 R15: 00007fff8de25338
 </TASK>
rcu: rcu_preempt kthread starved for 10602 jiffies! g84121 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:27128 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5392 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6781
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6961
 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6985
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
 prepare_to_swait_event+0x341/0x380 kernel/sched/swait.c:119
 rcu_gp_fqs_loop+0x2cc/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
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: 0 Comm: swapper/0 Not tainted 6.15.0-syzkaller-11061-g7f9039c524a3 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:queued_write_lock_slowpath+0x120/0x260 kernel/locking/qrwlock.c:85
Code: c1 f6 f0 81 0b 00 01 00 00 43 0f b6 04 27 84 c0 74 35 89 d9 80 e1 07 80 c1 03 38 c1 7c 29 48 89 df e8 44 71 c1 f6 eb 1f f3 90 <43> 0f b6 04 27 84 c0 74 14 89 d9 80 e1 07 80 c1 03 38 c1 7c 08 48
RSP: 0018:ffffc900000079c0 EFLAGS: 00000206
RAX: 0000000000000300 RBX: ffff88807b6532e8 RCX: ffffffff8b603618
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88807b6532e8
RBP: ffffc90000007a70 R08: ffff88807b6532eb R09: 1ffff1100f6ca65d
R10: dffffc0000000000 R11: ffffed100f6ca65e R12: dffffc0000000000
R13: 1ffff92000000f3c R14: ffffc90000007a10 R15: 1ffff1100f6ca65d
FS:  0000000000000000(0000) GS:ffff888125c93000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001e80 CR3: 000000003136a000 CR4: 00000000003526f0
DR0: 0000000000000007 DR1: ffffffffffffffff DR2: 0000000000000008
DR3: 1000000100000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 queued_write_lock include/asm-generic/qrwlock.h:101 [inline]
 do_raw_write_lock+0x1f2/0x260 kernel/locking/spinlock_debug.c:211
 wg_socket_clear_peer_endpoint_src+0x1e/0x50 drivers/net/wireguard/socket.c:310
 wg_expired_retransmit_handshake+0xd4/0x2d0 drivers/net/wireguard/timers.c:73
 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
 expire_timers kernel/time/timer.c:1798 [inline]
 __run_timers kernel/time/timer.c:2372 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
 run_timer_base kernel/time/timer.c:2393 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc 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 a3 a5 2a 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c2
RAX: 463b41559438bf00 RBX: ffffffff81974cf8 RCX: 463b41559438bf00
RDX: 0000000000000001 RSI: ffffffff8d95ca94 RDI: ffffffff8be1a080
RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb
R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8f9fb6f0
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:743
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
 rest_init+0x2de/0x300 init/main.c:744
 start_kernel+0x47d/0x500 init/main.c:1101
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
 common_startup_64+0x13e/0x147
 </TASK>