ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 kobject: kobject_add_internal failed for hci0:201 with -EEXIST, don't try to register things with the same name in the same directory. Bluetooth: hci0: failed to register connection device ================================================================== BUG: KASAN: slab-use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1639 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x902/0x1560 net/bluetooth/l2cap_core.c:7419 Read of size 8 at addr ffff88803b91a500 by task kworker/u9:2/8775 CPU: 1 UID: 0 PID: 8775 Comm: kworker/u9:2 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: hci0 hci_rx_work 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 l2cap_conn_ready net/bluetooth/l2cap_core.c:1639 [inline] l2cap_connect_cfm+0x902/0x1560 net/bluetooth/l2cap_core.c:7419 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0x1134/0x16b0 net/bluetooth/hci_event.c:5865 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5891 hci_event_func net/bluetooth/hci_event.c:7793 [inline] hci_event_packet+0x659/0xef0 net/bluetooth/hci_event.c:7847 hci_rx_work+0x3ee/0x1040 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 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 Allocated by task 8775: 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] __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5420 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] l2cap_chan_create+0x51/0x7a0 net/bluetooth/l2cap_core.c:445 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1980 [inline] l2cap_sock_new_connection_cb+0x191/0x2f0 net/bluetooth/l2cap_sock.c:1550 l2cap_connect_cfm+0x368/0x1560 net/bluetooth/l2cap_core.c:7402 hci_connect_cfm+0x95/0x140 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0x1134/0x16b0 net/bluetooth/hci_event.c:5865 hci_le_conn_complete_evt+0x187/0x470 net/bluetooth/hci_event.c:5891 hci_event_func net/bluetooth/hci_event.c:7793 [inline] hci_event_packet+0x659/0xef0 net/bluetooth/hci_event.c:7847 hci_rx_work+0x3ee/0x1040 net/bluetooth/hci_core.c:4077 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 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 11607: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 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:2689 [inline] slab_free mm/slub.c:6251 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6566 l2cap_sock_destruct+0x97/0x2c0 net/bluetooth/l2cap_sock.c:1864 __sk_destruct+0x8d/0x9d0 net/core/sock.c:2352 sock_put include/net/sock.h:2010 [inline] l2cap_sock_cleanup_listen+0x1d9/0x580 net/bluetooth/l2cap_sock.c:-1 l2cap_sock_release+0x6e/0x270 net/bluetooth/l2cap_sock.c:1456 __sock_release net/socket.c:722 [inline] sock_close+0xc3/0x240 net/socket.c:1514 __fput+0x461/0xa70 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xf3/0x4d0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0x560 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803b91a000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1280 bytes inside of freed 2048-byte region [ffff88803b91a000, ffff88803b91a800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88803b91d000 pfn:0x3b918 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000240(workingset|head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000240 ffff88801a011000 ffffea00017ca410 ffffea0000acfc10 raw: ffff88803b91d000 0000000800080007 00000000f5000000 0000000000000000 head: 0080000000000240 ffff88801a011000 ffffea00017ca410 ffffea0000acfc10 head: ffff88803b91d000 0000000800080007 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5653, tgid 5653 (syz-executor), ts 323700883745, free_ts 323698531228 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x27c8/0x2840 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7272 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4652 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_node_track_caller_noprof+0x60b/0x7e0 mm/slub.c:5408 kmalloc_reserve net/core/skbuff.c:635 [inline] pskb_expand_head+0x230/0x1390 net/core/skbuff.c:2303 netlink_trim+0x1b3/0x2c0 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0x80/0xea0 net/netlink/af_netlink.c:1512 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2593 __dev_notify_flags+0xf2/0x310 net/core/dev.c:9793 rtnl_configure_link+0x22c/0x350 net/core/rtnetlink.c:3630 veth_newlink+0x52f/0xb70 drivers/net/veth.c:1871 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3864 __rtnl_newlink net/core/rtnetlink.c:3995 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4110 page last free pid 5653 tgid 5653 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xfa6/0x10f0 mm/page_alloc.c:2943 __slab_free+0x252/0x2a0 mm/slub.c:5613 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:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] __kmalloc_cache_noprof+0x338/0x690 mm/slub.c:5415 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] kset_create lib/kobject.c:965 [inline] kset_create_and_add+0x5a/0x180 lib/kobject.c:1008 register_queue_kobjects net/core/net-sysfs.c:2091 [inline] netdev_register_kobject+0x1a2/0x310 net/core/net-sysfs.c:2347 register_netdevice+0x146d/0x1ed0 net/core/dev.c:11423 veth_newlink+0x4a4/0xb70 drivers/net/veth.c:1861 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3864 __rtnl_newlink net/core/rtnetlink.c:3995 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4110 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6997 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x780/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 Memory state around the buggy address: ffff88803b91a400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803b91a480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803b91a500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803b91a580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803b91a600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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