watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [aoe_tx0:2427] Modules linked in: irq event stamp: 66861607 hardirqs last enabled at (66861606): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] hardirqs last enabled at (66861606): [] _raw_spin_unlock_irqrestore+0x38/0x98 kernel/locking/spinlock.c:194 hardirqs last disabled at (66861607): [] __enter_from_kernel_mode arch/arm64/kernel/entry-common.c:43 [inline] hardirqs last disabled at (66861607): [] enter_from_kernel_mode+0x14/0x34 arch/arm64/kernel/entry-common.c:50 softirqs last enabled at (1396): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (1400): [] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19 CPU: 0 UID: 0 PID: 2427 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025 pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : raw_atomic_try_cmpxchg include/linux/atomic/atomic-arch-fallback.h:2140 [inline] pc : raw_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:2431 [inline] pc : raw_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:2456 [inline] pc : atomic_add_unless include/linux/atomic/atomic-instrumented.h:1518 [inline] pc : uart_port_ref drivers/tty/serial/serial_core.c:67 [inline] pc : uart_port_ref_lock+0x74/0x35c drivers/tty/serial/serial_core.c:80 lr : __lse__cmpxchg_case_mb_32 arch/arm64/include/asm/atomic_lse.h:279 [inline] lr : __cmpxchg_case_mb_32 arch/arm64/include/asm/cmpxchg.h:128 [inline] lr : __cmpxchg_mb arch/arm64/include/asm/cmpxchg.h:171 [inline] lr : raw_atomic_cmpxchg include/linux/atomic/atomic-arch-fallback.h:2026 [inline] lr : raw_atomic_try_cmpxchg include/linux/atomic/atomic-arch-fallback.h:2139 [inline] lr : raw_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:2431 [inline] lr : raw_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:2456 [inline] lr : atomic_add_unless include/linux/atomic/atomic-instrumented.h:1518 [inline] lr : uart_port_ref drivers/tty/serial/serial_core.c:67 [inline] lr : uart_port_ref_lock+0x6c/0x35c drivers/tty/serial/serial_core.c:80 sp : ffff8000a23e7710 x29: ffff8000a23e7710 x28: ffff0000eec75930 x27: 0000000000000000 x26: ffff0000eec758c0 x25: 0000000000000001 x24: dfff800000000000 x23: 0000000000000002 x22: 0000000000000001 x21: ffff0000c99d0f84 x20: ffff8000a23e7760 x19: ffff0000c99d0be8 x18: 00000000ffffffff x17: ffff800093605000 x16: ffff80008052bc24 x15: 0000000000000001 x14: 1fffe0001933a1f0 x13: 0000000000000000 x12: 0000000000000000 x11: ffff60001933a1f1 x10: 0000000000ff0100 x9 : 0000000000000000 x8 : ffff0000cd2e9e80 x7 : ffff800083e3d860 x6 : 0000000000000000 x5 : 0000000000000001 x4 : 0000000000000001 x3 : ffff800083e3d7c0 x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000000 Call trace: __lse__cmpxchg_case_mb_32 arch/arm64/include/asm/atomic_lse.h:279 [inline] (P) __cmpxchg_case_mb_32 arch/arm64/include/asm/cmpxchg.h:128 [inline] (P) __cmpxchg_mb arch/arm64/include/asm/cmpxchg.h:171 [inline] (P) raw_atomic_cmpxchg include/linux/atomic/atomic-arch-fallback.h:2026 [inline] (P) raw_atomic_try_cmpxchg include/linux/atomic/atomic-arch-fallback.h:2139 [inline] (P) raw_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:2431 [inline] (P) raw_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:2456 [inline] (P) atomic_add_unless include/linux/atomic/atomic-instrumented.h:1518 [inline] (P) uart_port_ref drivers/tty/serial/serial_core.c:67 [inline] (P) uart_port_ref_lock+0x74/0x35c drivers/tty/serial/serial_core.c:80 (P) uart_write+0x70/0x130 drivers/tty/serial/serial_core.c:627 handle_tx+0x200/0x5fc drivers/net/caif/caif_serial.c:222 caif_xmit+0x108/0x150 drivers/net/caif/caif_serial.c:268 __netdev_start_xmit include/linux/netdevice.h:5222 [inline] netdev_start_xmit include/linux/netdevice.h:5231 [inline] xmit_one net/core/dev.c:3839 [inline] dev_hard_start_xmit+0x2b0/0x890 net/core/dev.c:3855 __dev_queue_xmit+0x1600/0x32a8 net/core/dev.c:4725 dev_queue_xmit include/linux/netdevice.h:3361 [inline] tx+0x9c/0x1cc drivers/block/aoe/aoenet.c:62 kthread+0x164/0x354 drivers/block/aoe/aoecmd.c:1241 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6649 Comm: kworker/1:5 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025 Workqueue: events ser_release pstate: 03400005 (nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : queued_spin_lock_slowpath+0x138/0xaec kernel/locking/qspinlock.c:197 lr : queued_spin_lock_slowpath+0x144/0xaec kernel/locking/qspinlock.c:197 sp : ffff8000a3cd7460 x29: ffff8000a3cd7500 x28: 1fffe0001f8c6fa9 x27: 1fffe0001937ab72 x26: ffff0000c9bd5b80 x25: dfff800000000000 x24: ffff70001479ae90 x23: 0000000000000000 x22: ffff0000c9bd5b90 x21: ffff0000fc637d48 x20: ffff0000fc637d50 x19: ffff0000fc637d40 x18: 00000000ffffffff x17: ffff800093605000 x16: ffff800080537d14 x15: 0000000000000001 x14: 1fffe0001f8c6fa8 x13: 0000000000000000 x12: 0000000000000000 x11: ffff60001f8c6fa9 x10: dfff800000000000 x9 : 0000000000000000 x8 : 0000000000000001 x7 : ffff800089524ab4 x6 : 0000000000000000 x5 : 0000000000000020 x4 : ffff8000a3cd7420 x3 : ffff80008b0885f8 x2 : 0000000000000000 x1 : 0000000000000001 x0 : 0000000000000001 Call trace: __cmpwait_case_8 arch/arm64/include/asm/cmpxchg.h:229 [inline] (P) __cmpwait arch/arm64/include/asm/cmpxchg.h:257 [inline] (P) queued_spin_lock_slowpath+0x138/0xaec kernel/locking/qspinlock.c:197 (P) queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x2a8/0x2cc kernel/locking/spinlock_debug.c:116 __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline] _raw_spin_lock+0x50/0x60 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] __netif_tx_lock include/linux/netdevice.h:4659 [inline] netif_freeze_queues net/sched/sch_generic.c:461 [inline] netif_tx_lock+0x9c/0x1d8 net/sched/sch_generic.c:470 netif_tx_lock_bh include/linux/netdevice.h:4744 [inline] netdev_watchdog_down net/sched/sch_generic.c:570 [inline] dev_deactivate_many+0x274/0xabc net/sched/sch_generic.c:1370 __dev_close_many+0x238/0x704 net/core/dev.c:1739 netif_close_many+0x1e8/0x448 net/core/dev.c:1780 netif_close+0x148/0x1f8 net/core/dev.c:1797 dev_close+0xf8/0x1e4 net/core/dev_api.c:220 ser_release+0x150/0x1ec drivers/net/caif/caif_serial.c:295 process_one_work+0x7e8/0x155c kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3400 kthread+0x5fc/0x75c kernel/kthread.c:463 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844