watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.0.10:5932] Modules linked in: irq event stamp: 11759743 hardirqs last enabled at (11759742): [] irqentry_exit+0x74/0x90 kernel/entry/common.c:357 hardirqs last disabled at (11759743): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1049 softirqs last enabled at (11306862): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last enabled at (11306862): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last enabled at (11306862): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 softirqs last disabled at (11306865): [] __do_softirq kernel/softirq.c:613 [inline] softirqs last disabled at (11306865): [] invoke_softirq kernel/softirq.c:453 [inline] softirqs last disabled at (11306865): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 CPU: 0 UID: 0 PID: 5932 Comm: syz.0.10 Not tainted 6.15.0-rc4-syzkaller-gb4432656b36e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 RIP: 0010:perf_trace_buf_alloc+0x198/0x2a0 kernel/trace/trace_event_perf.c:416 Code: 4c 89 f7 e8 ba 96 58 00 4d 8b 36 e8 72 d4 8c 09 89 c5 41 89 c7 bf 08 00 00 00 89 c6 e8 e1 a5 f6 ff 83 fd 07 0f 87 b5 00 00 00 93 a1 f6 ff 4e 8d 3c fd 10 dc 96 8d 4c 89 f8 48 c1 e8 03 42 80 RSP: 0018:ffffc90000006660 EFLAGS: 00000297 RAX: ffffffff81c91d2f RBX: 000000000000002c RCX: 0000000000000100 RDX: ffff88801e3a3c00 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 0000000000000000 R08: ffffc90003227ef0 R09: 0000000000000000 R10: ffffc90000006938 R11: fffff52000000d29 R12: ffffffff8d96dc10 R13: dffffc0000000000 R14: 0000607ed9bc7000 R15: 0000000000000000 FS: 00007f49947896c0(0000) GS:ffff8881260cc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f81dff8 CR3: 000000002d52a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_perf_trace_lock include/trace/events/lock.h:50 [inline] perf_trace_lock+0x18d/0x3b0 include/trace/events/lock.h:50 __do_trace_lock_release include/trace/events/lock.h:69 [inline] trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x3b2/0x3e0 kernel/locking/lockdep.c:5877 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 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 mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2398 [inline] slab_free mm/slub.c:4656 [inline] kmem_cache_free+0x192/0x3f0 mm/slub.c:4758 skb_release_all net/core/skbuff.c:1160 [inline] __kfree_skb net/core/skbuff.c:1176 [inline] sk_skb_reason_drop+0xe9/0x170 net/core/skbuff.c:1214 kfree_skb_reason include/linux/skbuff.h:1279 [inline] kfree_skb include/linux/skbuff.h:1288 [inline] ip6_mc_input+0x9c3/0xbe0 net/ipv6/ip6_input.c:591 ip_sabotage_in+0x1de/0x270 net/bridge/br_netfilter_hooks.c:993 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc2/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:312 __netif_receive_skb_one_core net/core/dev.c:5887 [inline] __netif_receive_skb+0xd3/0x380 net/core/dev.c:6000 netif_receive_skb_internal net/core/dev.c:6086 [inline] netif_receive_skb+0x1cb/0x790 net/core/dev.c:6145 NF_HOOK+0x9d/0x390 include/linux/netfilter.h:315 br_handle_frame_finish+0x1489/0x1950 net/bridge/br_input.c:-1 br_nf_hook_thresh+0x3bf/0x490 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x948/0xd00 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0x97f/0x14c0 net/bridge/br_input.c:433 __netif_receive_skb_core+0x10de/0x4180 net/core/dev.c:5773 __netif_receive_skb_one_core net/core/dev.c:5885 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6000 process_backlog+0x60e/0x14f0 net/core/dev.c:6352 __napi_poll+0xc4/0x480 net/core/dev.c:7324 napi_poll net/core/dev.c:7388 [inline] net_rx_action+0x6ea/0xdf0 net/core/dev.c:7510 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_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0xa3/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738 RIP: 0010:__schedule+0x171c/0x4cd0 kernel/sched/core.c:6774 Code: c7 48 8b b4 24 c0 00 00 00 e8 c0 21 3b f6 48 c7 84 24 00 01 00 00 0e 36 e0 45 48 8b 84 24 f8 00 00 00 4a c7 04 28 00 00 00 00 <4a> c7 44 28 09 00 00 00 00 42 c7 44 28 11 00 00 00 00 66 42 c7 44 RSP: 0018:ffffc900032279a0 EFLAGS: 00000202 RAX: 1ffff92000644f54 RBX: ffff88801e3a4380 RCX: 734ec99771b61a00 RDX: 0000000000000000 RSI: ffffffff8bc1cdc0 RDI: ffffffff8bc1cd80 RBP: ffffc90003227bb0 R08: ffffffff8f7ed377 R09: 1ffffffff1efda6e R10: dffffc0000000000 R11: fffffbfff1efda6f R12: ffff88801e3a3c00 R13: dffffc0000000000 R14: ffff88801e3a3c00 R15: ffff8880b8839b40 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090 irqentry_exit+0x6f/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:get_unused_fd_flags+0x0/0x80 fs/file.c:606 Code: 4c 89 f7 e8 82 56 e7 ff e9 83 fd ff ff e8 b8 60 85 ff 90 0f 0b 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 41 54 53 89 fb 49 bc 00 00 00 00 00 fc ff RSP: 0018:ffffc90003227d38 EFLAGS: 00000202 RAX: ffffffff81ef9ea3 RBX: 0000000000000000 RCX: ffff88801e3a3c00 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc90003227ef0 R08: ffff88801b28f103 R09: 1ffff11003651e20 R10: dffffc0000000000 R11: ffffed1003651e21 R12: ffffffffffffffff R13: 0000000000005d31 R14: 0000000000000000 R15: 1ffff92000644fb4 __do_sys_perf_event_open kernel/events/core.c:13137 [inline] __se_sys_perf_event_open+0x45c/0x1c80 kernel/events/core.c:13061 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f499398e969 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:00007f4994789038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f4993bb5fa0 RCX: 00007f499398e969 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480 RBP: 00007f4993a10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4993bb5fa0 R15: 00007ffc31c72288 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 18 Comm: rcu_exp_gp_kthr Not tainted 6.15.0-rc4-syzkaller-gb4432656b36e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409 Code: e8 1e 40 82 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ff 34 e4 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07 RSP: 0018:ffffc90000177578 EFLAGS: 00000006 RAX: 1ffffffff3369705 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc90000177750 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff853d7e60 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff99b4bbc0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881261cc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa19a439bd0 CR3: 000000002f994000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:791 [inline] serial8250_console_write+0x581/0x1ba0 drivers/tty/serial/8250/8250_port.c:3420 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 _printk+0xcf/0x120 kernel/printk/printk.c:2475 synchronize_rcu_expedited_stall+0x61/0x1170 kernel/rcu/tree_exp.h:570 synchronize_rcu_expedited_wait kernel/rcu/tree_exp.h:668 [inline] rcu_exp_wait_wake kernel/rcu/tree_exp.h:687 [inline] rcu_exp_sel_wait_wake+0x7a1/0xd40 kernel/rcu/tree_exp.h:721 kthread_worker_fn+0x504/0xb60 kernel/kthread.c:1010 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245