------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 9 at lib/refcount.c:25 refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: netns cleanup_net pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 lr : refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 sp : ffff800008007800 x29: ffff800008007800 x28: ffff0000e7179000 x27: ffff0000cc5dd000 x26: 1fffe0001812a001 x25: dfff800000000000 x24: 1fffe000198bba01 x23: ffff0000cf387c00 x22: ffff0000c1da8154 x21: ffff0000c13e4880 x20: ffff0000c1da8154 x19: ffff80001659e000 x18: 0000000000000101 x17: 0000000000000000 x16: ffff8000111a97c4 x15: 00000000ffffffff x14: 0000000000ff0100 x13: 0000000000000001 x12: 0000000000ff0100 x11: 0000000000000100 x10: 0000000000000000 x9 : 4cb61e4e29394600 x8 : 4cb61e4e29394600 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff8000080070f8 x4 : ffff80001423f280 x3 : ffff800008503958 x2 : 0000000000000001 x1 : 0000000000000100 x0 : 000000000000002a Call trace: refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] get_net include/net/net_namespace.h:252 [inline] tipc_aead_encrypt net/tipc/crypto.c:832 [inline] tipc_crypto_xmit+0x1634/0x2220 net/tipc/crypto.c:1772 tipc_bearer_xmit_skb+0x1f0/0x384 net/tipc/bearer.c:574 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338 call_timer_fn+0x19c/0x858 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x46c/0x6c4 kernel/time/timer.c:1767 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1780 handle_softirqs+0x344/0xbf0 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] invoke_softirq kernel/softirq.c:457 [inline] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 irq_exit+0x14/0x88 kernel/softirq.c:683 handle_domain_irq+0x14c/0x1fc kernel/irq/irqdesc.c:711 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:765 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899 do_interrupt_handler+0x6c/0x88 arch/arm64/kernel/entry-common.c:267 el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522 __sanitizer_cov_trace_pc+0xa8/0xac kernel/kcov.c:216 batadv_hard_if_event+0x8c/0xddc net/batman-adv/hard-interface.c:955 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:2049 [inline] call_netdevice_notifiers_extack net/core/dev.c:2061 [inline] call_netdevice_notifiers+0x10c/0x18c net/core/dev.c:2075 udp_tunnel_get_rx_info include/net/udp_tunnel.h:138 [inline] udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:830 [inline] udp_tunnel_nic_netdevice_event+0x8bc/0x1378 net/ipv4/udp_tunnel_nic.c:898 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:2049 [inline] call_netdevice_notifiers_extack net/core/dev.c:2061 [inline] call_netdevice_notifiers+0x10c/0x18c net/core/dev.c:2075 register_netdevice+0xf04/0x1304 net/core/dev.c:10428 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:317 [inline] nsim_create+0x2bc/0x36c drivers/net/netdevsim/netdev.c:365 __nsim_dev_port_add+0x4a8/0x7cc drivers/net/netdevsim/dev.c:1312 nsim_dev_port_add_all+0x4c/0x124 drivers/net/netdevsim/dev.c:1372 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1421 [inline] nsim_dev_reload_up+0x3f8/0x660 drivers/net/netdevsim/dev.c:910 devlink_reload+0x288/0x5c8 net/core/devlink.c:3970 devlink_pernet_pre_exit+0x194/0x33c net/core/devlink.c:11543 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x470/0xa98 net/core/net_namespace.c:615 process_one_work+0x79c/0x1140 kernel/workqueue.c:2310 worker_thread+0x8f4/0x101c kernel/workqueue.c:2457 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 irq event stamp: 275795 hardirqs last enabled at (275794): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:257 hardirqs last disabled at (275795): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396 softirqs last enabled at (275764): [] spin_unlock_bh include/linux/spinlock.h:408 [inline] softirqs last enabled at (275764): [] clusterip_netdev_event+0x384/0x3ac net/ipv4/netfilter/ipt_CLUSTERIP.c:233 softirqs last disabled at (275767): [] __do_softirq kernel/softirq.c:610 [inline] softirqs last disabled at (275767): [] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (275767): [] invoke_softirq kernel/softirq.c:457 [inline] softirqs last disabled at (275767): [] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 ---[ end trace daad18604789981a ]--- ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 9 at lib/refcount.c:28 refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 9 Comm: kworker/u4:0 Tainted: G W 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: netns cleanup_net pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 lr : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 sp : ffff800008007800 x29: ffff800008007800 x28: ffff0000e7179000 x27: 0000000000000000 x26: 1fffe0001812a001 x25: dfff800000000000 x24: 1fffe000198bba01 x23: ffff0000f19e9038 x22: ffff0000c1da8000 x21: ffff0000c13e4880 x20: ffff0000c1da8154 x19: ffff80001659e000 x18: 0000000000000101 x17: 0000000000000000 x16: ffff8000083008fc x15: 00000000ffffffff x14: 0000000000ff0100 x13: 0000000000000001 x12: 0000000000ff0100 x11: 0000000000000100 x10: 0000000000000000 x9 : 4cb61e4e29394600 x8 : 4cb61e4e29394600 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff8000080070f8 x4 : ffff80001423f280 x3 : ffff800008300a0c x2 : 0000000000000001 x1 : 0000000000000100 x0 : 0000000000000026 Call trace: refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] put_net include/net/net_namespace.h:270 [inline] tipc_aead_encrypt net/tipc/crypto.c:840 [inline] tipc_crypto_xmit+0x177c/0x2220 net/tipc/crypto.c:1772 tipc_bearer_xmit_skb+0x1f0/0x384 net/tipc/bearer.c:574 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338 call_timer_fn+0x19c/0x858 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x46c/0x6c4 kernel/time/timer.c:1767 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1780 handle_softirqs+0x344/0xbf0 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] invoke_softirq kernel/softirq.c:457 [inline] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 irq_exit+0x14/0x88 kernel/softirq.c:683 handle_domain_irq+0x14c/0x1fc kernel/irq/irqdesc.c:711 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:765 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899 do_interrupt_handler+0x6c/0x88 arch/arm64/kernel/entry-common.c:267 el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522 __sanitizer_cov_trace_pc+0xa8/0xac kernel/kcov.c:216 batadv_hard_if_event+0x8c/0xddc net/batman-adv/hard-interface.c:955 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:2049 [inline] call_netdevice_notifiers_extack net/core/dev.c:2061 [inline] call_netdevice_notifiers+0x10c/0x18c net/core/dev.c:2075 udp_tunnel_get_rx_info include/net/udp_tunnel.h:138 [inline] udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:830 [inline] udp_tunnel_nic_netdevice_event+0x8bc/0x1378 net/ipv4/udp_tunnel_nic.c:898 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:2049 [inline] call_netdevice_notifiers_extack net/core/dev.c:2061 [inline] call_netdevice_notifiers+0x10c/0x18c net/core/dev.c:2075 register_netdevice+0xf04/0x1304 net/core/dev.c:10428 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:317 [inline] nsim_create+0x2bc/0x36c drivers/net/netdevsim/netdev.c:365 __nsim_dev_port_add+0x4a8/0x7cc drivers/net/netdevsim/dev.c:1312 nsim_dev_port_add_all+0x4c/0x124 drivers/net/netdevsim/dev.c:1372 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1421 [inline] nsim_dev_reload_up+0x3f8/0x660 drivers/net/netdevsim/dev.c:910 devlink_reload+0x288/0x5c8 net/core/devlink.c:3970 devlink_pernet_pre_exit+0x194/0x33c net/core/devlink.c:11543 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x470/0xa98 net/core/net_namespace.c:615 process_one_work+0x79c/0x1140 kernel/workqueue.c:2310 worker_thread+0x8f4/0x101c kernel/workqueue.c:2457 kthread+0x374/0x454 kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 irq event stamp: 275825 hardirqs last enabled at (275824): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:257 hardirqs last disabled at (275825): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396 softirqs last enabled at (275764): [] spin_unlock_bh include/linux/spinlock.h:408 [inline] softirqs last enabled at (275764): [] clusterip_netdev_event+0x384/0x3ac net/ipv4/netfilter/ipt_CLUSTERIP.c:233 softirqs last disabled at (275767): [] __do_softirq kernel/softirq.c:610 [inline] softirqs last disabled at (275767): [] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (275767): [] invoke_softirq kernel/softirq.c:457 [inline] softirqs last disabled at (275767): [] __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659 ---[ end trace daad18604789981b ]---