================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_ready_cb+0xc8/0x164 net/bluetooth/l2cap_sock.c:1714 Read of size 8 at addr ffff0000d7abe188 by task kworker/u9:3/4678 CPU: 0 UID: 0 PID: 4678 Comm: kworker/u9:3 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: hci2 hci_rx_work Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xb0/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0x8c/0xc4 mm/kasan/report.c:595 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 l2cap_sock_ready_cb+0xc8/0x164 net/bluetooth/l2cap_sock.c:1714 l2cap_chan_ready+0x18c/0x1fc net/bluetooth/l2cap_core.c:1279 l2cap_le_start+0x708/0xba4 net/bluetooth/l2cap_core.c:1391 l2cap_conn_ready net/bluetooth/l2cap_core.c:1644 [inline] l2cap_connect_cfm+0x554/0xb94 net/bluetooth/l2cap_core.c:7427 hci_connect_cfm+0x98/0x134 include/net/bluetooth/hci_core.h:2139 le_conn_complete_evt+0xc78/0x109c net/bluetooth/hci_event.c:5865 hci_le_conn_complete_evt+0x114/0x40c net/bluetooth/hci_event.c:5891 hci_le_meta_evt+0x2d4/0x49c net/bluetooth/hci_event.c:7506 hci_event_func net/bluetooth/hci_event.c:7770 [inline] hci_event_packet+0x4e4/0xa00 net/bluetooth/hci_event.c:7824 hci_rx_work+0x2fc/0xd1c net/bluetooth/hci_core.c:4077 process_one_work+0x78c/0x173c kernel/workqueue.c:3302 process_scheduled_works+0xdc/0x13c kernel/workqueue.c:3385 worker_thread+0x770/0xbd0 kernel/workqueue.c:3466 kthread+0x2f0/0x3c0 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:842 Allocated by task 7918: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:570 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_noprof+0x2dc/0x638 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] sk_prot_alloc+0xc4/0x1ec net/core/sock.c:2247 sk_alloc+0x44/0x3a0 net/core/sock.c:2303 bt_sock_alloc+0x4c/0x2f8 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc+0x4c/0x168 net/bluetooth/l2cap_sock.c:1925 l2cap_sock_create+0x134/0x20c net/bluetooth/l2cap_sock.c:1967 bt_sock_create+0x14c/0x240 net/bluetooth/af_bluetooth.c:135 __sock_create+0x2fc/0x640 net/socket.c:1664 sock_create net/socket.c:1722 [inline] __sys_socket_create+0xc0/0x11c net/socket.c:1759 __sys_socket+0x44/0xec net/socket.c:1806 __do_sys_socket net/socket.c:1820 [inline] __se_sys_socket net/socket.c:1818 [inline] __arm64_sys_socket+0x7c/0x94 net/socket.c:1818 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x60/0x25c arch/arm64/kernel/entry-common.c:723 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:742 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Freed by task 7918: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x74/0xa4 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:6246 [inline] kfree+0x188/0x5e4 mm/slub.c:6561 sk_prot_free net/core/sock.c:2286 [inline] __sk_destruct+0x5a4/0x84c net/core/sock.c:2386 sk_destruct+0x88/0xb4 net/core/sock.c:2414 __sk_free+0x2c4/0x3bc net/core/sock.c:2425 sk_free+0x60/0xc4 net/core/sock.c:2436 sock_put include/net/sock.h:2010 [inline] l2cap_sock_kill+0x12c/0x254 net/bluetooth/l2cap_sock.c:1290 l2cap_sock_release+0x15c/0x1f8 net/bluetooth/l2cap_sock.c:1463 __sock_release+0xa0/0x1d4 net/socket.c:722 sock_close+0x24/0x38 net/socket.c:1514 __fput+0x340/0x744 fs/file_table.c:510 ____fput+0x20/0x30 fs/file_table.c:538 task_work_run+0x1c4/0x254 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+0x10c/0x17c kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] exit_to_user_mode_prepare_legacy include/linux/irq-entry-common.h:224 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:86 [inline] el0_svc+0x180/0x25c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:742 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 The buggy address belongs to the object at ffff0000d7abe000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 392 bytes inside of freed 2048-byte region [ffff0000d7abe000, ffff0000d7abe800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff0000d7abc000 pfn:0x117ab8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000240(workingset|head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000240 ffff0000c0002000 fffffdffc36bf210 fffffdffc3c74e10 raw: ffff0000d7abc000 0000000800080005 00000000f5000000 0000000000000000 head: 05ffc00000000240 ffff0000c0002000 fffffdffc36bf210 fffffdffc3c74e10 head: ffff0000d7abc000 0000000800080005 00000000f5000000 0000000000000000 head: 05ffc00000000003 fffffdffc35eae01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000d7abe080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000d7abe100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000d7abe180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000d7abe200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000d7abe280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Bluetooth: hci2: Ignoring HCI_Connection_Complete for existing connection