============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:2023 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_del+0xcf2/0x1770 net/ipv6/ip6_fib.c:2023 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:2035 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_del+0x2ef/0x1770 net/ipv6/ip6_fib.c:2035 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1921 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_del_route net/ipv6/ip6_fib.c:1921 [inline] fib6_del+0x1084/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1930 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_del_route net/ipv6/ip6_fib.c:1930 [inline] fib6_del+0xfef/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1975 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 10 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 #9: ffff88803116cd38 (&net->ipv6.fib6_walker_lock){++..}-{3:3}, at: fib6_del_route net/ipv6/ip6_fib.c:1971 [inline] #9: ffff88803116cd38 (&net->ipv6.fib6_walker_lock){++..}-{3:3}, at: fib6_del+0x880/0x1770 net/ipv6/ip6_fib.c:2040 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_del_route net/ipv6/ip6_fib.c:1975 [inline] fib6_del+0x1281/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1805 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_repair_tree.part.0+0x5f2/0x1270 net/ipv6/ip6_fib.c:1805 fib6_repair_tree net/ipv6/ip6_fib.c:1799 [inline] fib6_del_route net/ipv6/ip6_fib.c:1992 [inline] fib6_del+0x133d/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1807 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_repair_tree.part.0+0x564/0x1270 net/ipv6/ip6_fib.c:1807 fib6_repair_tree net/ipv6/ip6_fib.c:1799 [inline] fib6_del_route net/ipv6/ip6_fib.c:1992 [inline] fib6_del+0x133d/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1809 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_repair_tree.part.0+0x4d6/0x1270 net/ipv6/ip6_fib.c:1809 fib6_repair_tree net/ipv6/ip6_fib.c:1799 [inline] fib6_del_route net/ipv6/ip6_fib.c:1992 [inline] fib6_del+0x133d/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1811 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_repair_tree.part.0+0x447/0x1270 net/ipv6/ip6_fib.c:1811 fib6_repair_tree net/ipv6/ip6_fib.c:1799 [inline] fib6_del_route net/ipv6/ip6_fib.c:1992 [inline] fib6_del+0x133d/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1813 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_repair_tree.part.0+0x710/0x1270 net/ipv6/ip6_fib.c:1813 fib6_repair_tree net/ipv6/ip6_fib.c:1799 [inline] fib6_del_route net/ipv6/ip6_fib.c:1992 [inline] fib6_del+0x133d/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1815 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_repair_tree.part.0+0x681/0x1270 net/ipv6/ip6_fib.c:1815 fib6_repair_tree net/ipv6/ip6_fib.c:1799 [inline] fib6_del_route net/ipv6/ip6_fib.c:1992 [inline] fib6_del+0x133d/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1817 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_repair_tree.part.0+0x79f/0x1270 net/ipv6/ip6_fib.c:1817 fib6_repair_tree net/ipv6/ip6_fib.c:1799 [inline] fib6_del_route net/ipv6/ip6_fib.c:1992 [inline] fib6_del+0x133d/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1766 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000154fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90110950 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880574410e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x12c/0x2b0 net/devlink/core.c:506 #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880557b6250 (&devlink->lock_key#59){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x136/0x2b0 net/devlink/core.c:506 #5: ffffffff901267e8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xfc/0x5d0 drivers/net/netdevsim/netdev.c:1059 #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2751 [inline] #6: ffff88802876cd30 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1653/0x26f0 net/core/dev.c:11941 #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #8: ffff888026294430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 0 UID: 0 PID: 62 Comm: kworker/u8:4 Not tainted 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_find_prefix.part.0+0x1ee/0x3e0 net/ipv6/ip6_fib.c:1766 fib6_find_prefix net/ipv6/ip6_fib.c:1762 [inline] fib6_repair_tree.part.0+0x2c9/0x1270 net/ipv6/ip6_fib.c:1845 fib6_repair_tree net/ipv6/ip6_fib.c:1799 [inline] fib6_del_route net/ipv6/ip6_fib.c:1992 [inline] fib6_del+0x133d/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x384/0x26f0 net/core/dev.c:11944 unregister_netdevice_many net/core/dev.c:12046 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11889 unregister_netdevice include/linux/netdevice.h:3374 [inline] nsim_destroy+0x197/0x5d0 drivers/net/netdevsim/netdev.c:1064 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x10a/0x4d0 drivers/net/netdevsim/dev.c:1661 nsim_dev_reload_down+0x6e/0xd0 drivers/net/netdevsim/dev.c:968 devlink_reload+0x1a1/0x7c0 net/devlink/dev.c:461 devlink_pernet_pre_exit+0x1a0/0x2b0 net/devlink/core.c:509 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x497/0xb30 net/core/net_namespace.c:634 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00291-g2a239ffbebb5 #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1768 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 9 locks held by kworker/u8:4/62: