watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.9.3502:18982] Modules linked in: irq event stamp: 13563121 hardirqs last enabled at (13563120): [] irqentry_exit+0x74/0x90 kernel/entry/common.c:214 hardirqs last disabled at (13563121): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1052 softirqs last enabled at (13390602): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last enabled at (13390602): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last enabled at (13390602): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 softirqs last disabled at (13390607): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last disabled at (13390607): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last disabled at (13390607): [] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 CPU: 0 UID: 0 PID: 18982 Comm: syz.9.3502 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x28/0x70 kernel/kcov.c:217 Code: 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 60 49 92 65 8b 15 b8 e0 8a 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 <83> b9 7c 16 00 00 00 74 2c 8b 91 58 16 00 00 83 fa 02 75 21 48 8b RSP: 0000:ffffc90000006f00 EFLAGS: 00000246 RAX: ffffffff81c2c945 RBX: 0000000000000000 RCX: ffff888029e90000 RDX: 0000000000000100 RSI: 0000000000000200 RDI: 0000000000000000 RBP: ffffc90000006ff0 R08: ffffc900000071cf R09: 0000000000000000 R10: ffffc900000071c0 R11: fffff52000000e3a R12: dffffc0000000000 R13: 1ffff92000000dec R14: 00000000000000ec R15: 0000000000000000 FS: 00007f98733ea6c0(0000) GS:ffff88812638a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000060afa000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: tracing_gen_ctx_irq_test+0x15/0x160 kernel/trace/trace.c:2589 tracing_gen_ctx_flags include/linux/trace_events.h:200 [inline] tracing_gen_ctx include/linux/trace_events.h:207 [inline] perf_trace_buf_update+0x9f/0x220 kernel/trace/trace_event_perf.c:429 perf_tp_event+0xf6/0x1380 kernel/events/core.c:10998 perf_trace_run_bpf_submit+0xee/0x170 kernel/events/core.c:10936 do_perf_trace_lock_acquire include/trace/events/lock.h:24 [inline] perf_trace_lock_acquire+0x335/0x410 include/trace/events/lock.h:24 __do_trace_lock_acquire include/trace/events/lock.h:24 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x311/0x360 kernel/locking/lockdep.c:5831 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:1169 [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 mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4946 [inline] slab_alloc_node mm/slub.c:5245 [inline] kmem_cache_alloc_node_noprof+0x433/0x710 mm/slub.c:5297 kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:579 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1383 [inline] ndisc_alloc_skb+0x9f/0x480 net/ipv6/ndisc.c:420 ndisc_send_rs+0x2b5/0x630 net/ipv6/ndisc.c:706 addrconf_rs_timer+0x369/0x670 net/ipv6/addrconf.c:4037 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:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 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 52 8a a3 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: 0000:ffffc9000524efe0 EFLAGS: 00000206 RAX: 2d21e748b1cd5800 RBX: 1ffff92000a49e00 RCX: 2d21e748b1cd5800 RDX: 0000000000000007 RSI: ffffffff8d512c0f RDI: ffffffff8b9eea60 RBP: ffffc9000524f0b8 R08: ffffffff8f5bed37 R09: 1ffffffff1eb7da6 R10: dffffc0000000000 R11: fffffbfff1eb7da7 R12: ffffffff8dd40400 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __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:1169 [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:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:559 __call_rcu_common kernel/rcu/tree.c:3123 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3243 context_switch kernel/sched/core.c:5328 [inline] __schedule+0x17a0/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:sched_mm_cid_exit_signals+0x320/0x4b0 kernel/sched/core.c:10842 Code: a4 35 00 48 c7 44 24 60 00 00 00 00 9c 8f 44 24 60 f6 44 24 61 02 75 57 f7 c3 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00 RSP: 0000:ffffc9000524fa20 EFLAGS: 00000206 RAX: 2d21e748b1cd5800 RBX: 0000000000000246 RCX: 2d21e748b1cd5800 RDX: 0000000000000007 RSI: ffffffff8d512c0f RDI: ffffffff8b9eea60 RBP: ffffc9000524fb08 R08: ffffffff8f5bed37 R09: 1ffffffff1eb7da6 R10: dffffc0000000000 R11: fffffbfff1eb7da7 R12: 1ffff92000a49f4c R13: dffffc0000000000 R14: ffff888029e915cc R15: dffffc0000000000 exit_signals+0x374/0x600 kernel/signal.c:3128 do_exit+0x352/0x2300 kernel/exit.c:913 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:40 [inline] exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] irqentry_exit_to_user_mode+0x7e/0x110 kernel/entry/common.c:73 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0033:0x7f987258eec9 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:00007f98733ea038 EFLAGS: 00000246 RAX: 0000000000000010 RBX: 00007f98727e5fa0 RCX: 00007f987258eec9 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000010 RBP: 00007f9872611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f98727e6038 R14: 00007f98727e5fa0 R15: 00007ffe10adca28 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5849 Comm: kworker/u9:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: hci4 hci_cmd_timeout RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 ee 27 af 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 9f ca 14 fd 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:ffffc9000438f318 EFLAGS: 00000006 RAX: 1ffffffff3313505 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc9000438f4f0 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff850f5720 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff9989af40 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812648a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555578c445c8 CR3: 000000007b1f2000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: serial_port_in include/linux/serial_core.h:793 [inline] serial8250_console_write+0x581/0x1ba0 drivers/tty/serial/8250/8250_port.c:3360 console_emit_next_record kernel/printk/printk.c:3111 [inline] console_flush_all+0x6f0/0xb10 kernel/printk/printk.c:3199 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3298 vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423 _printk+0xcf/0x120 kernel/printk/printk.c:2448 bt_err+0x10b/0x160 net/bluetooth/lib.c:296 hci_cmd_timeout+0xd8/0x1e0 net/bluetooth/hci_core.c:1469 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245