------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 4976 at lib/refcount.c:25 refcount_warn_saturate+0x134/0x1f8 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 4976 Comm: kworker/u4:15 Not tainted 6.1.141-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 : ffff8000080078c0 x29: ffff8000080078c0 x28: ffff0000cf9a7400 x27: ffff0000def88a08 x26: ffff0000d9e59770 x25: dfff800000000000 x24: 1fffe0001bdf1141 x23: ffff0000c3051400 x22: ffff0000f0a139d4 x21: ffff0000f3a38080 x20: ffff0000f0a139d4 x19: ffff800017a32000 x18: 000000009199cbd0 x17: 0000000000000000 x16: ffff8000082d1c00 x15: 0000000000000000 x14: 00000000ffffffff x13: 0000000000000001 x12: 0000000000ff0100 x11: ff0080000819149c x10: 0000000000000000 x9 : 4387c36b25d09700 x8 : 4387c36b25d09700 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800008007358 x4 : ffff800015154700 x3 : ffff80000852da40 x2 : 0000000000000001 x1 : 0000000100000100 x0 : 0000000000000000 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:257 [inline] tipc_aead_encrypt net/tipc/crypto.c:821 [inline] tipc_crypto_xmit+0x1518/0x2014 net/tipc/crypto.c:1761 tipc_bearer_xmit_skb+0x1f0/0x384 net/tipc/bearer.c:574 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338 call_timer_fn+0x1b8/0x964 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x460/0x6bc kernel/time/timer.c:1820 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1833 handle_softirqs+0x318/0xc6c kernel/softirq.c:596 __do_softirq+0x14/0x20 kernel/softirq.c:630 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:893 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85 invoke_softirq kernel/softirq.c:477 [inline] __irq_exit_rcu+0x23c/0x43c kernel/softirq.c:679 irq_exit_rcu+0x14/0x84 kernel/softirq.c:691 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline] el1_interrupt+0x38/0x54 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581 write_comp_data kernel/kcov.c:268 [inline] __sanitizer_cov_trace_const_cmp8+0x9c/0xa8 kernel/kcov.c:320 arch_stack_walk+0x190/0x1dc arch/arm64/kernel/stacktrace.c:231 stack_trace_save+0x94/0xd8 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:52 kasan_save_free_info+0x3c/0x60 mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:236 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x16c/0x1ec mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] kmem_cache_free+0x11c/0x324 mm/slub.c:3683 kernfs_put+0x2f4/0x4a0 fs/kernfs/dir.c:568 kernfs_remove_by_name_ns+0xe8/0x184 fs/kernfs/dir.c:1667 kernfs_remove_by_name include/linux/kernfs.h:622 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xf8/0x288 fs/sysfs/group.c:288 sysfs_remove_groups+0x5c/0xb4 fs/sysfs/group.c:312 __kobject_del+0x90/0x2d4 lib/kobject.c:587 kobject_cleanup lib/kobject.c:672 [inline] kobject_release lib/kobject.c:712 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x2c8/0x438 lib/kobject.c:729 netdev_queue_update_kobjects+0x3b8/0x440 net/core/net-sysfs.c:1731 remove_queue_kobjects net/core/net-sysfs.c:1828 [inline] netdev_unregister_kobject+0xf0/0x204 net/core/net-sysfs.c:1981 unregister_netdevice_many+0x1194/0x1740 net/core/dev.c:11005 unregister_netdevice_queue+0x2ac/0x2f8 net/core/dev.c:10909 unregister_netdevice include/linux/netdevice.h:3075 [inline] nsim_destroy+0x58/0x164 drivers/net/netdevsim/netdev.c:382 __nsim_dev_port_del+0x144/0x1a4 drivers/net/netdevsim/dev.c:1433 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1445 [inline] nsim_dev_reload_destroy+0x240/0x43c drivers/net/netdevsim/dev.c:1662 nsim_dev_reload_down+0x9c/0xd4 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1b4/0x570 net/devlink/leftover.c:4472 devlink_pernet_pre_exit+0x118/0x2a8 net/devlink/leftover.c:12501 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x470/0xa74 net/core/net_namespace.c:620 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864 irq event stamp: 4090037 hardirqs last enabled at (4090036): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:261 hardirqs last disabled at (4090037): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405 softirqs last enabled at (4089704): [] spin_unlock_bh include/linux/spinlock.h:396 [inline] softirqs last enabled at (4089704): [] netif_addr_unlock_bh include/linux/netdevice.h:4510 [inline] softirqs last enabled at (4089704): [] dev_mc_flush+0x1b0/0x1f4 net/core/dev_addr_lists.c:1036 softirqs last disabled at (4089779): [] __do_softirq+0x14/0x20 kernel/softirq.c:630 ---[ end trace 0000000000000000 ]--- ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 4976 at lib/refcount.c:28 refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 4976 Comm: kworker/u4:15 Tainted: G W 6.1.141-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 : ffff8000080078c0 x29: ffff8000080078c0 x28: ffff0000cf9a7400 x27: 0000000000000000 x26: ffff0000d9e59770 x25: dfff800000000000 x24: 1fffe0001b3cb2f8 x23: 1fffe0001a347a69 x22: ffff0000def88a00 x21: 00000000c0000000 x20: ffff0000f0a139d4 x19: ffff800017a32000 x18: 000000009199cbd0 x17: 0000000000000000 x16: ffff8000082d1c00 x15: 0000000000000000 x14: 00000000ffffffff x13: 0000000000000001 x12: 0000000000ff0100 x11: ff0080000819149c x10: 0000000000000000 x9 : 4387c36b25d09700 x8 : 4387c36b25d09700 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800008007358 x4 : ffff800015154700 x3 : ffff8000083115f4 x2 : 0000000000000001 x1 : 0000000000000100 x0 : 0000000000000000 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:276 [inline] tipc_aead_encrypt net/tipc/crypto.c:829 [inline] tipc_crypto_xmit+0x1664/0x2014 net/tipc/crypto.c:1761 tipc_bearer_xmit_skb+0x1f0/0x384 net/tipc/bearer.c:574 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338 call_timer_fn+0x1b8/0x964 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x460/0x6bc kernel/time/timer.c:1820 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1833 handle_softirqs+0x318/0xc6c kernel/softirq.c:596 __do_softirq+0x14/0x20 kernel/softirq.c:630 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:893 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85 invoke_softirq kernel/softirq.c:477 [inline] __irq_exit_rcu+0x23c/0x43c kernel/softirq.c:679 irq_exit_rcu+0x14/0x84 kernel/softirq.c:691 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline] el1_interrupt+0x38/0x54 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581 write_comp_data kernel/kcov.c:268 [inline] __sanitizer_cov_trace_const_cmp8+0x9c/0xa8 kernel/kcov.c:320 arch_stack_walk+0x190/0x1dc arch/arm64/kernel/stacktrace.c:231 stack_trace_save+0x94/0xd8 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:52 kasan_save_free_info+0x3c/0x60 mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:236 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x16c/0x1ec mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] kmem_cache_free+0x11c/0x324 mm/slub.c:3683 kernfs_put+0x2f4/0x4a0 fs/kernfs/dir.c:568 kernfs_remove_by_name_ns+0xe8/0x184 fs/kernfs/dir.c:1667 kernfs_remove_by_name include/linux/kernfs.h:622 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xf8/0x288 fs/sysfs/group.c:288 sysfs_remove_groups+0x5c/0xb4 fs/sysfs/group.c:312 __kobject_del+0x90/0x2d4 lib/kobject.c:587 kobject_cleanup lib/kobject.c:672 [inline] kobject_release lib/kobject.c:712 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x2c8/0x438 lib/kobject.c:729 netdev_queue_update_kobjects+0x3b8/0x440 net/core/net-sysfs.c:1731 remove_queue_kobjects net/core/net-sysfs.c:1828 [inline] netdev_unregister_kobject+0xf0/0x204 net/core/net-sysfs.c:1981 unregister_netdevice_many+0x1194/0x1740 net/core/dev.c:11005 unregister_netdevice_queue+0x2ac/0x2f8 net/core/dev.c:10909 unregister_netdevice include/linux/netdevice.h:3075 [inline] nsim_destroy+0x58/0x164 drivers/net/netdevsim/netdev.c:382 __nsim_dev_port_del+0x144/0x1a4 drivers/net/netdevsim/dev.c:1433 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1445 [inline] nsim_dev_reload_destroy+0x240/0x43c drivers/net/netdevsim/dev.c:1662 nsim_dev_reload_down+0x9c/0xd4 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1b4/0x570 net/devlink/leftover.c:4472 devlink_pernet_pre_exit+0x118/0x2a8 net/devlink/leftover.c:12501 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x470/0xa74 net/core/net_namespace.c:620 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864 irq event stamp: 4090073 hardirqs last enabled at (4090072): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:261 hardirqs last disabled at (4090073): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405 softirqs last enabled at (4089704): [] spin_unlock_bh include/linux/spinlock.h:396 [inline] softirqs last enabled at (4089704): [] netif_addr_unlock_bh include/linux/netdevice.h:4510 [inline] softirqs last enabled at (4089704): [] dev_mc_flush+0x1b0/0x1f4 net/core/dev_addr_lists.c:1036 softirqs last disabled at (4089779): [] __do_softirq+0x14/0x20 kernel/softirq.c:630 ---[ end trace 0000000000000000 ]--- ------------[ cut here ]------------ refcount_t: saturated; leaking memory. WARNING: CPU: 0 PID: 4976 at lib/refcount.c:22 refcount_warn_saturate+0x1b4/0x1f8 lib/refcount.c:22 Modules linked in: CPU: 0 PID: 4976 Comm: kworker/u4:15 Tainted: G W 6.1.141-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+0x1b4/0x1f8 lib/refcount.c:22 lr : refcount_warn_saturate+0x1b4/0x1f8 lib/refcount.c:22 sp : ffff8000080078c0 x29: ffff8000080078c0 x28: ffff0000cf9a7800 x27: ffff0000def88a08 x26: ffff0000d9e59c70 x25: dfff800000000000 x24: 1fffe0001bdf1141 x23: ffff0000c3052c00 x22: ffff0000f0a139d4 x21: 000000007ffffffe x20: ffff0000f0a139d4 x19: ffff800017a32000 x18: 000000009199cbd0 x17: 0000000000000000 x16: ffff8000082d1c00 x15: 0000000000000000 x14: 00000000ffffffff x13: 0000000000000001 x12: 0000000000ff0100 x11: ff0080000819149c x10: 0000000000000000 x9 : 4387c36b25d09700 x8 : 4387c36b25d09700 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800008007358 x4 : ffff800015154700 x3 : ffff8000083115f4 x2 : 0000000000000001 x1 : 0000000000000100 x0 : 0000000000000000 Call trace: refcount_warn_saturate+0x1b4/0x1f8 lib/refcount.c:22 __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:257 [inline] tipc_aead_encrypt net/tipc/crypto.c:821 [inline] tipc_crypto_xmit+0x1518/0x2014 net/tipc/crypto.c:1761 tipc_bearer_xmit_skb+0x1f0/0x384 net/tipc/bearer.c:574 tipc_disc_timeout+0x4c8/0x608 net/tipc/discover.c:338 call_timer_fn+0x1b8/0x964 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x460/0x6bc kernel/time/timer.c:1820 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1833 handle_softirqs+0x318/0xc6c kernel/softirq.c:596 __do_softirq+0x14/0x20 kernel/softirq.c:630 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:893 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85 invoke_softirq kernel/softirq.c:477 [inline] __irq_exit_rcu+0x23c/0x43c kernel/softirq.c:679 irq_exit_rcu+0x14/0x84 kernel/softirq.c:691 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline] el1_interrupt+0x38/0x54 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:581 write_comp_data kernel/kcov.c:268 [inline] __sanitizer_cov_trace_const_cmp8+0x9c/0xa8 kernel/kcov.c:320 arch_stack_walk+0x190/0x1dc arch/arm64/kernel/stacktrace.c:231 stack_trace_save+0x94/0xd8 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:52 kasan_save_free_info+0x3c/0x60 mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:236 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x16c/0x1ec mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] kmem_cache_free+0x11c/0x324 mm/slub.c:3683 kernfs_put+0x2f4/0x4a0 fs/kernfs/dir.c:568 kernfs_remove_by_name_ns+0xe8/0x184 fs/kernfs/dir.c:1667 kernfs_remove_by_name include/linux/kernfs.h:622 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xf8/0x288 fs/sysfs/group.c:288 sysfs_remove_groups+0x5c/0xb4 fs/sysfs/group.c:312 __kobject_del+0x90/0x2d4 lib/kobject.c:587 kobject_cleanup lib/kobject.c:672 [inline] kobject_release lib/kobject.c:712 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x2c8/0x438 lib/kobject.c:729 netdev_queue_update_kobjects+0x3b8/0x440 net/core/net-sysfs.c:1731 remove_queue_kobjects net/core/net-sysfs.c:1828 [inline] netdev_unregister_kobject+0xf0/0x204 net/core/net-sysfs.c:1981 unregister_netdevice_many+0x1194/0x1740 net/core/dev.c:11005 unregister_netdevice_queue+0x2ac/0x2f8 net/core/dev.c:10909 unregister_netdevice include/linux/netdevice.h:3075 [inline] nsim_destroy+0x58/0x164 drivers/net/netdevsim/netdev.c:382 __nsim_dev_port_del+0x144/0x1a4 drivers/net/netdevsim/dev.c:1433 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1445 [inline] nsim_dev_reload_destroy+0x240/0x43c drivers/net/netdevsim/dev.c:1662 nsim_dev_reload_down+0x9c/0xd4 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1b4/0x570 net/devlink/leftover.c:4472 devlink_pernet_pre_exit+0x118/0x2a8 net/devlink/leftover.c:12501 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x470/0xa74 net/core/net_namespace.c:620 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864 irq event stamp: 4090123 hardirqs last enabled at (4090122): [] __up_console_sem+0xb4/0x100 kernel/printk/printk.c:261 hardirqs last disabled at (4090123): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405 softirqs last enabled at (4089704): [] spin_unlock_bh include/linux/spinlock.h:396 [inline] softirqs last enabled at (4089704): [] netif_addr_unlock_bh include/linux/netdevice.h:4510 [inline] softirqs last enabled at (4089704): [] dev_mc_flush+0x1b0/0x1f4 net/core/dev_addr_lists.c:1036 softirqs last disabled at (4089779): [] __do_softirq+0x14/0x20 kernel/softirq.c:630 ---[ end trace 0000000000000000 ]---