================================================================== BUG: KASAN: slab-use-after-free in rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 Read of size 1 at addr ffff8880680307e8 by task syz.1.1706/11871 CPU: 0 UID: 0 PID: 11871 Comm: syz.1.1706 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:574 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5844 rt_spin_lock+0x83/0x400 kernel/locking/spinlock_rt.c:56 spin_lock_bh include/linux/spinlock_rt.h:90 [inline] bt_accept_unlink+0x7d/0x2f0 net/bluetooth/af_bluetooth.c:263 l2cap_sock_teardown_cb+0x17e/0x490 net/bluetooth/l2cap_sock.c:1711 l2cap_chan_del+0x98/0x600 net/bluetooth/l2cap_core.c:687 l2cap_conn_del+0x2f2/0x520 net/bluetooth/l2cap_core.c:1825 hci_disconn_cfm include/net/bluetooth/hci_core.h:2152 [inline] hci_conn_hash_flush+0x105/0x260 net/bluetooth/hci_conn.c:2733 hci_dev_close_sync+0x7fc/0x10a0 net/bluetooth/hci_sync.c:5381 hci_dev_do_close net/bluetooth/hci_core.c:502 [inline] hci_unregister_dev+0x232/0x5b0 net/bluetooth/hci_core.c:2681 vhci_release+0x170/0x1c0 drivers/bluetooth/hci_vhci.c:700 __fput+0x42a/0xa80 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1004 do_group_exit+0x22d/0x2f0 kernel/exit.c:1147 get_signal+0x121b/0x12c0 kernel/signal.c:3024 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop kernel/entry/common.c:101 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline] irqentry_exit+0x2ba/0x8f0 kernel/entry/common.c:165 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7f714b09de61 Code: Unable to access opcode bytes at 0x7f714b09de37. RSP: 002b:00000000fffffeb0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f714b325fa0 RCX: 00007f714b09de59 RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400 RBP: 00007f714b133e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f714b326038 R14: 00007f714b325fa0 R15: 00007fff0ddf7b48 Allocated by task 12: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5336 [inline] __kmalloc_node_track_caller_noprof+0x566/0x7b0 mm/slub.c:5473 kmalloc_reserve net/core/skbuff.c:637 [inline] __alloc_skb+0x2bd/0x7a0 net/core/skbuff.c:715 alloc_skb include/linux/skbuff.h:1384 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x2b1/0xcb0 drivers/net/netdevsim/dev.c:922 process_one_work+0xaaf/0x1480 kernel/workqueue.c:3375 process_scheduled_works kernel/workqueue.c:3458 [inline] worker_thread+0xb05/0x10d0 kernel/workqueue.c:3539 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 12: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2705 [inline] slab_free mm/slub.c:6381 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6696 skb_kfree_head net/core/skbuff.c:1077 [inline] skb_free_head net/core/skbuff.c:1089 [inline] skb_release_data+0x85e/0xab0 net/core/skbuff.c:1116 skb_release_all net/core/skbuff.c:1191 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1205 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline] nsim_dev_trap_report_work+0x879/0xcb0 drivers/net/netdevsim/dev.c:922 process_one_work+0xaaf/0x1480 kernel/workqueue.c:3375 process_scheduled_works kernel/workqueue.c:3458 [inline] worker_thread+0xb05/0x10d0 kernel/workqueue.c:3539 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff888068030000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2024 bytes inside of freed 4096-byte region [ffff888068030000, ffff888068031000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x68030 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813feb5140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813feb5140 dead000000000100 dead000000000122 head: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 9288, tgid 9287 (syz.4.1020), ts 429351761569 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1861 prep_new_page mm/page_alloc.c:1869 [inline] get_page_from_freelist+0x264c/0x26c0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x1a6/0x390 mm/page_alloc.c:5313 alloc_slab_page mm/slub.c:3294 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3408 new_slab mm/slub.c:3454 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7314 refill_sheaf mm/slub.c:2832 [inline] __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4697 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4907 [inline] __do_kmalloc_node mm/slub.c:5335 [inline] __kmalloc_node_track_caller_noprof+0x616/0x7b0 mm/slub.c:5473 kmalloc_reserve net/core/skbuff.c:637 [inline] __alloc_skb+0x2bd/0x7a0 net/core/skbuff.c:715 alloc_skb include/linux/skbuff.h:1384 [inline] nlmsg_new include/net/netlink.h:1055 [inline] rtmsg_ifinfo_build_skb+0x7f/0x260 net/core/rtnetlink.c:4524 rtmsg_ifinfo_event net/core/rtnetlink.c:4566 [inline] rtmsg_ifinfo+0x8c/0x1a0 net/core/rtnetlink.c:4575 register_netdevice+0x1ab1/0x1ed0 net/core/dev.c:11499 register_netdev+0x40/0x60 net/core/dev.c:11563 ip6_tnl_init_net+0x259/0x3b0 net/ipv6/ip6_tunnel.c:2357 ops_init+0x35d/0x5d0 net/core/net_namespace.c:137 setup_net+0x118/0x350 net/core/net_namespace.c:446 copy_net_ns+0x4f9/0x720 net/core/net_namespace.c:579 page last free pid 9288 tgid 9287 ts 429328216474 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1408 [inline] __free_frozen_pages+0x10de/0x11c0 mm/page_alloc.c:2952 __slab_free+0x252/0x2a0 mm/slub.c:5743 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4606 [inline] slab_alloc_node mm/slub.c:4919 [inline] kmem_cache_alloc_node_noprof+0x3f4/0x660 mm/slub.c:4991 kmalloc_reserve net/core/skbuff.c:615 [inline] __alloc_skb+0x276/0x7a0 net/core/skbuff.c:715 alloc_skb include/linux/skbuff.h:1384 [inline] nlmsg_new include/net/netlink.h:1055 [inline] inet6_netconf_notify_devconf+0x10f/0x1d0 net/ipv6/addrconf.c:593 __addrconf_sysctl_register+0x439/0x4b0 net/ipv6/addrconf.c:7377 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7414 ipv6_add_dev+0xd82/0x1420 net/ipv6/addrconf.c:460 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3685 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2289 [inline] call_netdevice_notifiers net/core/dev.c:2303 [inline] register_netdevice+0x18c0/0x1ed0 net/core/dev.c:11485 __ip_tunnel_create+0x3e8/0x550 net/ipv4/ip_tunnel.c:268 ip_tunnel_init_net+0x2e5/0x820 net/ipv4/ip_tunnel.c:1150 Memory state around the buggy address: ffff888068030680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888068030700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888068030780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888068030800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888068030880: fb fb fb fb fb fb fb fb fb fb fb fb 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