------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 9 at lib/refcount.c:25 refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 Modules linked in: CPU: 1 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 : ffff80001b2c6860 x29: ffff80001b2c6860 x28: ffff0000dad90000 x27: ffff0000ce355e00 x26: 1fffe0001812a001 x25: dfff800000000000 x24: 1fffe00019c6abc1 x23: ffff0000e874cc00 x22: ffff0000c1ef0154 x21: ffff0000cd429080 x20: ffff0000c1ef0154 x19: ffff80001659e000 x18: 0000000000000102 x17: 0000000000000000 x16: ffff8000111a97c4 x15: 00000000ffffffff x14: 0000000000ff0100 x13: 00000000000f40e0 x12: 0000000000ff0100 x11: 0000000000000101 x10: 0000000000000000 x9 : 63a6b0d955d40800 x8 : 63a6b0d955d40800 x7 : 00000000000f40e0 x6 : 00000000000f4080 x5 : ffff80001b2c6158 x4 : ffff800014236b38 x3 : ffff800008503958 x2 : 0000000000000001 x1 : 0000000000000101 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] do_softirq+0xfc/0x1b0 kernel/softirq.c:477 __local_bh_enable_ip+0x250/0x380 kernel/softirq.c:401 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0xec/0x174 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:408 [inline] __fib6_clean_all+0x1ec/0x320 net/ipv6/ip6_fib.c:2261 fib6_clean_all+0x3c/0x50 net/ipv6/ip6_fib.c:2270 rt6_sync_down_dev net/ipv6/route.c:4915 [inline] rt6_disable_ip+0x100/0x658 net/ipv6/route.c:4920 addrconf_ifdown+0x148/0x1688 net/ipv6/addrconf.c:3781 addrconf_notify+0x2f4/0xc6c net/ipv6/addrconf.c:-1 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 net/core/dev.c:2075 [inline] unregister_netdevice_many+0xe10/0x17d0 net/core/dev.c:11134 unregister_netdevice_queue+0x2ac/0x2f8 net/core/dev.c:11067 unregister_netdevice include/linux/netdevice.h:3020 [inline] nsim_destroy+0x58/0x164 drivers/net/netdevsim/netdev.c:382 __nsim_dev_port_del+0x144/0x1a4 drivers/net/netdevsim/dev.c:1349 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1362 [inline] nsim_dev_reload_destroy+0x144/0x204 drivers/net/netdevsim/dev.c:1561 nsim_dev_reload_down+0xe8/0x154 drivers/net/netdevsim/dev.c:883 devlink_reload+0x1e8/0x5c8 net/core/devlink.c:3963 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: 3747917 hardirqs last enabled at (3747916): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:257 hardirqs last disabled at (3747917): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396 softirqs last enabled at (3747888): [] spin_unlock_bh include/linux/spinlock.h:408 [inline] softirqs last enabled at (3747888): [] __fib6_clean_all+0x1ec/0x320 net/ipv6/ip6_fib.c:2261 softirqs last disabled at (3747889): [] __do_softirq kernel/softirq.c:610 [inline] softirqs last disabled at (3747889): [] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (3747889): [] do_softirq+0xfc/0x1b0 kernel/softirq.c:477 ---[ end trace 5aa71d68c2f5af5f ]--- ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 9 at lib/refcount.c:28 refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 Modules linked in: CPU: 1 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 : ffff80001b2c6860 x29: ffff80001b2c6860 x28: ffff0000dad90000 x27: 0000000000000000 x26: 1fffe0001812a001 x25: dfff800000000000 x24: 1fffe00019c6abc1 x23: ffff0000d89cc138 x22: ffff0000c1ef0000 x21: ffff0000cd429080 x20: ffff0000c1ef0154 x19: ffff80001659e000 x18: 0000000000000102 x17: 0000000000000000 x16: ffff8000083008fc x15: 00000000ffffffff x14: 0000000000ff0100 x13: 00000000000f5748 x12: 0000000000ff0100 x11: 0000000000000101 x10: 0000000000000000 x9 : 63a6b0d955d40800 x8 : 63a6b0d955d40800 x7 : 00000000000f5748 x6 : 00000000000f56e8 x5 : ffff80001b2c6158 x4 : ffff8000142370d8 x3 : ffff800008300a0c x2 : 0000000000000001 x1 : 0000000000000101 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] do_softirq+0xfc/0x1b0 kernel/softirq.c:477 __local_bh_enable_ip+0x250/0x380 kernel/softirq.c:401 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0xec/0x174 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:408 [inline] __fib6_clean_all+0x1ec/0x320 net/ipv6/ip6_fib.c:2261 fib6_clean_all+0x3c/0x50 net/ipv6/ip6_fib.c:2270 rt6_sync_down_dev net/ipv6/route.c:4915 [inline] rt6_disable_ip+0x100/0x658 net/ipv6/route.c:4920 addrconf_ifdown+0x148/0x1688 net/ipv6/addrconf.c:3781 addrconf_notify+0x2f4/0xc6c net/ipv6/addrconf.c:-1 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 net/core/dev.c:2075 [inline] unregister_netdevice_many+0xe10/0x17d0 net/core/dev.c:11134 unregister_netdevice_queue+0x2ac/0x2f8 net/core/dev.c:11067 unregister_netdevice include/linux/netdevice.h:3020 [inline] nsim_destroy+0x58/0x164 drivers/net/netdevsim/netdev.c:382 __nsim_dev_port_del+0x144/0x1a4 drivers/net/netdevsim/dev.c:1349 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1362 [inline] nsim_dev_reload_destroy+0x144/0x204 drivers/net/netdevsim/dev.c:1561 nsim_dev_reload_down+0xe8/0x154 drivers/net/netdevsim/dev.c:883 devlink_reload+0x1e8/0x5c8 net/core/devlink.c:3963 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: 3747943 hardirqs last enabled at (3747942): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:257 hardirqs last disabled at (3747943): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396 softirqs last enabled at (3747888): [] spin_unlock_bh include/linux/spinlock.h:408 [inline] softirqs last enabled at (3747888): [] __fib6_clean_all+0x1ec/0x320 net/ipv6/ip6_fib.c:2261 softirqs last disabled at (3747889): [] __do_softirq kernel/softirq.c:610 [inline] softirqs last disabled at (3747889): [] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (3747889): [] do_softirq+0xfc/0x1b0 kernel/softirq.c:477 ---[ end trace 5aa71d68c2f5af60 ]---