vxcan1: j1939_xtp_rx_abort_one: 0x0000000017fe64f5: 0x00100: (3) A timeout occurred and this is the connection abort to close the session. ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 13 at lib/refcount.c:28 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28 Modules linked in: CPU: 0 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted 6.12.0-syzkaller-g7b1d1d4cfac0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: netns cleanup_net pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28 lr : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28 sp : ffff8000800076d0 x29: ffff8000800076d0 x28: 0000000000000001 x27: 00000000ffffffff x26: 1fffe0001df35198 x25: dfff800000000000 x24: 0000000000000000 x23: ffff0000d5593ae4 x22: ffff80008a63b670 x21: 0000000000000003 x20: ffff0000d5593ae4 x19: ffff800092b74000 x18: 0000000000000008 x17: 0000000000000000 x16: ffff8000831615b0 x15: 0000000000000001 x14: 1ffff00010000e20 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000102 x10: 0000000000ff0100 x9 : d91b814bc3e87800 x8 : d91b814bc3e87800 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800080006df8 x4 : ffff80008f9bd220 x3 : ffff8000830fd570 x2 : 0000000000000001 x1 : 0000000100000100 x0 : 0000000000000000 Call trace: refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28 (P) refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28 (L) __refcount_sub_and_test include/linux/refcount.h:275 [inline] __refcount_dec_and_test include/linux/refcount.h:307 [inline] refcount_dec_and_test include/linux/refcount.h:325 [inline] skb_unref include/linux/skbuff.h:1232 [inline] __sk_skb_reason_drop net/core/skbuff.c:1213 [inline] sk_skb_reason_drop+0x210/0x43c net/core/skbuff.c:1241 kfree_skb_reason include/linux/skbuff.h:1262 [inline] kfree_skb include/linux/skbuff.h:1271 [inline] j1939_session_destroy net/can/j1939/transport.c:282 [inline] __j1939_session_release net/can/j1939/transport.c:294 [inline] kref_put include/linux/kref.h:65 [inline] j1939_session_put+0x1c8/0x460 net/can/j1939/transport.c:299 j1939_xtp_rx_abort_one+0xd4/0x358 net/can/j1939/transport.c:1354 j1939_xtp_rx_abort net/can/j1939/transport.c:1362 [inline] j1939_tp_cmd_recv net/can/j1939/transport.c:2128 [inline] j1939_tp_recv+0x814/0xe14 net/can/j1939/transport.c:2161 j1939_can_recv+0x5bc/0x934 net/can/j1939/main.c:108 deliver net/can/af_can.c:572 [inline] can_rcv_filter+0x308/0x714 net/can/af_can.c:606 can_receive+0x328/0x488 net/can/af_can.c:663 can_rcv+0x128/0x240 net/can/af_can.c:687 __netif_receive_skb_one_core net/core/dev.c:5670 [inline] __netif_receive_skb+0x18c/0x3c8 net/core/dev.c:5783 process_backlog+0x640/0x123c net/core/dev.c:6115 __napi_poll+0xb4/0x3fc net/core/dev.c:6779 napi_poll net/core/dev.c:6848 [inline] net_rx_action+0x6a8/0xf4c net/core/dev.c:6970 handle_softirqs+0x2e0/0xbf8 kernel/softirq.c:554 __do_softirq+0x14/0x20 kernel/softirq.c:588 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:81 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:891 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:86 invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0x1d8/0x544 kernel/softirq.c:655 irq_exit_rcu+0x14/0x84 kernel/softirq.c:671 __el1_irq arch/arm64/kernel/entry-common.c:561 [inline] el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:575 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:580 el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:596 __daif_local_irq_restore arch/arm64/include/asm/irqflags.h:175 [inline] (P) arch_local_irq_restore arch/arm64/include/asm/irqflags.h:195 [inline] (P) lockdep_unregister_key+0x3b0/0x46c kernel/locking/lockdep.c:6567 (P) lockdep_unregister_key+0x3a4/0x46c kernel/locking/lockdep.c:6566 (L) __qdisc_destroy+0x170/0x4d8 net/sched/sch_generic.c:1085 qdisc_put net/sched/sch_generic.c:1111 [inline] dev_shutdown+0x360/0x480 net/sched/sch_generic.c:1499 unregister_netdevice_many_notify+0x834/0x1c64 net/core/dev.c:11396 unregister_netdevice_many net/core/dev.c:11469 [inline] default_device_exit_batch+0xa00/0xa80 net/core/dev.c:11952 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x6b8/0x9b4 net/core/net_namespace.c:626 process_one_work+0x7bc/0x1600 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x97c/0xeec kernel/workqueue.c:3391 kthread+0x288/0x310 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 irq event stamp: 1122321 hardirqs last enabled at (1122320): [] __up_console_sem kernel/printk/printk.c:344 [inline] hardirqs last enabled at (1122320): [] __console_unlock+0x70/0xc4 kernel/printk/printk.c:2844 hardirqs last disabled at (1122321): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:488 softirqs last enabled at (1121644): [] spin_unlock_bh include/linux/spinlock.h:396 [inline] softirqs last enabled at (1121644): [] netif_addr_unlock_bh include/linux/netdevice.h:4534 [inline] softirqs last enabled at (1121644): [] dev_mc_flush+0x1b4/0x1f8 net/core/dev_addr_lists.c:1036 softirqs last disabled at (1122209): [] __do_softirq+0x14/0x20 kernel/softirq.c:588 ---[ end trace 0000000000000000 ]---