watchdog: BUG: soft lockup - CPU#0 stuck for 144s! [syz.4.1894:11850] Modules linked in: irq event stamp: 14883801 hardirqs last enabled at (14883800): [] irqentry_exit+0x74/0x90 kernel/entry/common.c:200 hardirqs last disabled at (14883801): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1050 softirqs last enabled at (13215342): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last enabled at (13215342): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last enabled at (13215342): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 softirqs last disabled at (13215345): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last disabled at (13215345): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last disabled at (13215345): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 CPU: 0 UID: 0 PID: 11850 Comm: syz.4.1894 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0x58/0x360 kernel/locking/lockdep.c:5831 Code: 8b 05 bc 42 03 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 bf 42 03 11 83 f8 08 0f 83 b8 01 00 00 89 c0 48 0f a3 05 a8 36 06 0e <73> 16 e8 61 02 09 00 84 c0 75 0d f6 05 d2 1b f0 0d 01 0f 84 d7 01 RSP: 0018:ffffc90000006e18 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e13a0e0 RBP: ffffffff8172d195 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90000006ac8 R11: ffffffff81ac4b00 R12: 0000000000000002 R13: ffffffff8e13a0e0 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f3a350086c0(0000) GS:ffff888125c15000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000002100 CR3: 0000000030a70000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3123 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3243 refdst_drop include/net/dst.h:263 [inline] skb_dst_drop include/net/dst.h:275 [inline] __dev_queue_xmit+0x85c/0x3b50 net/core/dev.c:4680 dev_queue_xmit include/linux/netdevice.h:3361 [inline] neigh_hh_output include/net/neighbour.h:531 [inline] neigh_output include/net/neighbour.h:545 [inline] ip6_finish_output2+0x11bc/0x16a0 net/ipv6/ip6_output.c:141 NF_HOOK include/linux/netfilter.h:318 [inline] ndisc_send_skb+0xb54/0x1440 net/ipv6/ndisc.c:512 addrconf_rs_timer+0x369/0x670 net/ipv6/addrconf.c:4037 call_timer_fn+0x17b/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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_read_unlock_special+0x87/0x4b0 kernel/rcu/tree_plugin.h:774 Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 d2 84 f9 10 41 f7 c6 00 00 f0 00 74 49 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b RSP: 0018:ffffc90003057260 EFLAGS: 00000206 RAX: 4f5ed20831096500 RBX: 1ffff9200060ae50 RCX: 4f5ed20831096500 RDX: 0000000000000000 RSI: ffffffff8d9b9eb1 RDI: ffffffff8be33d80 RBP: ffffc90003057338 R08: ffffffff8fa3a437 R09: 1ffffffff1f47486 R10: dffffc0000000000 R11: fffffbfff1f47487 R12: ffffffff8e13f401 R13: dffffc0000000000 R14: 0000000000000246 R15: ffff88801cb51e00 __rcu_read_unlock+0x84/0xe0 kernel/rcu/tree_plugin.h:438 rcu_read_unlock include/linux/rcupdate.h:873 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19ae/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3123 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3243 context_switch kernel/sched/core.c:5360 [inline] __schedule+0x17a0/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:_compound_head include/linux/page-flags.h:284 [inline] RIP: 0010:virt_to_folio include/linux/mm.h:1182 [inline] RIP: 0010:virt_to_slab mm/slab.h:187 [inline] RIP: 0010:__memcg_slab_post_alloc_hook+0x27e/0x7f0 mm/memcontrol.c:3171 Code: 10 4a 92 0b 4c 89 ff e8 40 4b 49 ff 49 89 c7 49 c1 ef 06 49 83 e7 c0 4f 8d 24 3e 49 83 c4 08 4c 89 e0 48 c1 e8 03 80 3c 28 00 <74> 08 4c 89 e7 e8 08 e7 f7 ff 49 8b 04 24 a8 01 0f 85 f5 02 00 00 RSP: 0018:ffffc90003057ca0 EFLAGS: 00000246 RAX: 1ffffd40001f2a89 RBX: ffffc90003057d78 RCX: 0000000000080000 RDX: ffffc9000c67a000 RSI: 0000000000000442 RDI: 0000000000000443 RBP: dffffc0000000000 R08: ffffc90003057897 R09: 0000000000000000 R10: ffffc90003057888 R11: fffff5200060af13 R12: ffffea0000f95448 R13: 0000000000000000 R14: ffffea0000000000 R15: 0000000000f95440 memcg_slab_post_alloc_hook mm/slub.c:2221 [inline] slab_post_alloc_hook mm/slub.c:4201 [inline] slab_alloc_node mm/slub.c:4240 [inline] kmem_cache_alloc_lru_noprof+0x2c7/0x3d0 mm/slub.c:4259 sock_alloc_inode+0x28/0xc0 net/socket.c:309 alloc_inode+0x67/0x1b0 fs/inode.c:346 new_inode_pseudo include/linux/fs.h:3392 [inline] sock_alloc net/socket.c:624 [inline] __sock_create+0x12d/0x9f0 net/socket.c:1553 sock_create net/socket.c:1647 [inline] __sys_socket_create net/socket.c:1684 [inline] __sys_socket+0xd7/0x1b0 net/socket.c:1731 __do_sys_socket net/socket.c:1745 [inline] __se_sys_socket net/socket.c:1743 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1743 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: 0033:0x7f3a3418eec9 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:00007f3a35008038 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f3a343e5fa0 RCX: 00007f3a3418eec9 RDX: 0000000000000010 RSI: 0000000000000003 RDI: 0000000000000010 RBP: 00007f3a34211f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3a343e6038 R14: 00007f3a343e5fa0 R15: 00007ffcbe1658a8 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5530 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d f4 65 fe 0b 48 89 de 5b e9 23 a1 58 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 b0 a0 92 65 8b 15 18 f1 e0 10 81 e2 00 01 ff 00 RSP: 0018:ffffc9000382f538 EFLAGS: 00000202 RAX: ffffffff81b4601b RBX: 1ffff110170c8341 RCX: ffff88802eaa1e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000382f6c0 R08: ffffffff8fa3a437 R09: 1ffffffff1f47486 R10: dffffc0000000000 R11: fffffbfff1f47487 R12: ffff8880b8641a08 R13: dffffc0000000000 R14: ffff8880b873b1c0 R15: 0000000000000000 FS: 00007fdf01f35740(0000) GS:ffff888125d15000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6499a4a54d CR3: 000000007de3a000 CR4: 00000000003526f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: csd_lock_wait kernel/smp.c:342 [inline] smp_call_function_many_cond+0xd4b/0x12d0 kernel/smp.c:877 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451 dup_mmap+0x15a0/0x1ac0 mm/mmap.c:1873 dup_mm kernel/fork.c:1485 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1537 copy_process+0x1706/0x3c00 kernel/fork.c:2175 kernel_clone+0x21e/0x840 kernel/fork.c:2605 __do_sys_clone kernel/fork.c:2748 [inline] __se_sys_clone kernel/fork.c:2732 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2732 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: 0033:0x7fdf02009636 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:00007ffe0fa165b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffe0fa165b8 RCX: 00007fdf02009636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffe0fa36b00 R08: 0000000000000000 R09: 0000000000000001 R10: 00007fdf01f35a10 R11: 0000000000000246 R12: 00007ffe0fa166f0 R13: 0000000000000000 R14: 0000000000000000 R15: 000055c97649aac0