kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 kobject_add_internal failed for hci1:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci1: failed to register connection device ================================================================== BUG: KASAN: use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1759 [inline] BUG: KASAN: use-after-free in l2cap_connect_cfm+0x6ff/0x10f0 net/bluetooth/l2cap_core.c:8321 Read of size 8 at addr ffff88801f625488 by task kworker/u5:4/4198 CPU: 0 PID: 4198 Comm: kworker/u5:4 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: hci1 hci_rx_work Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 l2cap_conn_ready net/bluetooth/l2cap_core.c:1759 [inline] l2cap_connect_cfm+0x6ff/0x10f0 net/bluetooth/l2cap_core.c:8321 hci_connect_cfm include/net/bluetooth/hci_core.h:1505 [inline] le_conn_complete_evt+0xd42/0x15c0 net/bluetooth/hci_event.c:5459 hci_le_conn_complete_evt net/bluetooth/hci_event.c:5484 [inline] hci_le_meta_evt+0x285/0x3c90 net/bluetooth/hci_event.c:6206 hci_event_packet+0xe48/0x1370 net/bluetooth/hci_event.c:6555 hci_rx_work+0x255/0xa10 net/bluetooth/hci_core.c:5164 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 4198: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] l2cap_chan_create+0x4c/0x730 net/bluetooth/l2cap_core.c:469 l2cap_sock_alloc+0x13a/0x200 net/bluetooth/l2cap_sock.c:1882 l2cap_sock_new_connection_cb+0xd1/0x1c0 net/bluetooth/l2cap_sock.c:1479 l2cap_connect_cfm+0x35d/0x10f0 net/bluetooth/l2cap_core.c:8304 hci_connect_cfm include/net/bluetooth/hci_core.h:1505 [inline] le_conn_complete_evt+0xd42/0x15c0 net/bluetooth/hci_event.c:5459 hci_le_conn_complete_evt net/bluetooth/hci_event.c:5484 [inline] hci_le_meta_evt+0x285/0x3c90 net/bluetooth/hci_event.c:6206 hci_event_packet+0xe48/0x1370 net/bluetooth/hci_event.c:6555 hci_rx_work+0x255/0xa10 net/bluetooth/hci_core.c:5164 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Freed by task 5392: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 l2cap_sock_cleanup_listen+0xea/0x270 net/bluetooth/l2cap_sock.c:1462 l2cap_sock_release+0x66/0x1e0 net/bluetooth/l2cap_sock.c:1420 __sock_release net/socket.c:651 [inline] sock_close+0xd5/0x240 net/socket.c:1345 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff88801f625000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1160 bytes inside of 2048-byte region [ffff88801f625000, ffff88801f625800) The buggy address belongs to the page: page:ffffea00007d8800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f620 head:ffffea00007d8800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888016c42000 raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4189, ts 54997168663, free_ts 54986330329 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] __kmalloc_node_track_caller+0x1fc/0x3a0 mm/slub.c:4963 kmalloc_reserve net/core/skbuff.c:356 [inline] pskb_expand_head+0x127/0x10f0 net/core/skbuff.c:1709 netlink_trim+0x180/0x220 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0x7c/0x1170 net/netlink/af_netlink.c:1511 netlink_broadcast net/netlink/af_netlink.c:1556 [inline] nlmsg_multicast include/net/netlink.h:1033 [inline] nlmsg_notify+0xec/0x1a0 net/netlink/af_netlink.c:2550 __dev_notify_flags+0xdc/0x300 net/core/dev.c:8900 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8942 do_setlink+0xcdb/0x3d60 net/core/rtnetlink.c:2781 __rtnl_newlink net/core/rtnetlink.c:3452 [inline] rtnl_newlink+0x1658/0x1a50 net/core/rtnetlink.c:3574 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5684 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 free_slab mm/slub.c:2020 [inline] discard_slab mm/slub.c:2026 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512 put_cpu_partial+0x12d/0x190 mm/slub.c:2592 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc+0x127/0x330 mm/slub.c:4408 kmalloc include/linux/slab.h:612 [inline] kzalloc include/linux/slab.h:738 [inline] fib_create_info+0xabc/0x24f0 net/ipv4/fib_semantics.c:1478 fib_table_insert+0xe4/0x1bb0 net/ipv4/fib_trie.c:1212 fib_magic+0x2e1/0x3c0 net/ipv4/fib_frontend.c:1106 fib_add_ifaddr+0x3f7/0x5e0 net/ipv4/fib_frontend.c:1150 fib_netdev_event+0x35c/0x480 net/ipv4/fib_frontend.c:1488 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline] call_netdevice_notifiers net/core/dev.c:2088 [inline] __dev_notify_flags+0x194/0x300 net/core/dev.c:8904 Memory state around the buggy address: ffff88801f625380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801f625400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801f625480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801f625500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801f625580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================