================================================================== BUG: KASAN: slab-use-after-free in l2cap_sock_ready_cb+0xd0/0x170 net/bluetooth/l2cap_sock.c:1787 Read of size 8 at addr ffff0000c972e188 by task kworker/u9:5/4718 CPU: 1 UID: 0 PID: 4718 Comm: kworker/u9:5 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 Workqueue: hci4 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+0xd0/0x170 net/bluetooth/l2cap_sock.c:1787 l2cap_chan_ready+0x190/0x200 net/bluetooth/l2cap_core.c:1308 l2cap_le_start+0x6dc/0xb74 net/bluetooth/l2cap_core.c:1420 l2cap_conn_ready net/bluetooth/l2cap_core.c:1673 [inline] l2cap_connect_cfm+0x518/0xb64 net/bluetooth/l2cap_core.c:7575 hci_connect_cfm+0x98/0x134 include/net/bluetooth/hci_core.h:2137 le_conn_complete_evt+0xca4/0x10f8 net/bluetooth/hci_event.c:5853 hci_le_conn_complete_evt+0x114/0x3d8 net/bluetooth/hci_event.c:5879 hci_le_meta_evt+0x2b0/0x46c net/bluetooth/hci_event.c:7517 hci_event_func net/bluetooth/hci_event.c:7781 [inline] hci_event_packet+0x4c0/0x9c8 net/bluetooth/hci_event.c:7835 hci_rx_work+0x2f4/0xd78 net/bluetooth/hci_core.c:4039 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0x788/0x10b8 kernel/workqueue.c:3405 worker_thread+0x798/0xbd0 kernel/workqueue.c:3486 kthread+0x304/0x3d4 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:842 Allocated by task 5966: 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:5362 [inline] __kmalloc_noprof+0x340/0x6b8 mm/slub.c:5387 _kmalloc_noprof include/linux/slab.h:973 [inline] sk_prot_alloc+0xc4/0x1e8 net/core/sock.c:2252 sk_alloc+0x44/0x3ac net/core/sock.c:2308 bt_sock_alloc+0x4c/0x324 net/bluetooth/af_bluetooth.c:148 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1980 [inline] l2cap_sock_create+0x150/0x2d0 net/bluetooth/l2cap_sock.c:2018 bt_sock_create+0x14c/0x240 net/bluetooth/af_bluetooth.c:132 __sock_create+0x31c/0x670 net/socket.c:1651 sock_create net/socket.c:1709 [inline] __sys_socket_create+0xc0/0x11c net/socket.c:1746 __sys_socket+0x44/0xec net/socket.c:1793 __do_sys_socket net/socket.c:1807 [inline] __se_sys_socket net/socket.c:1805 [inline] __arm64_sys_socket+0x7c/0x94 net/socket.c:1805 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Freed by task 5966: 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:2705 [inline] slab_free mm/slub.c:6405 [inline] kfree+0x188/0x690 mm/slub.c:6720 sk_prot_free net/core/sock.c:2291 [inline] __sk_destruct+0x5b0/0x854 net/core/sock.c:2391 sk_destruct+0x8c/0xb8 net/core/sock.c:2419 __sk_free+0x2c4/0x3bc net/core/sock.c:2430 sk_free+0x60/0xc4 net/core/sock.c:2441 sock_put include/net/sock.h:2020 [inline] l2cap_sock_kill+0x154/0x280 net/bluetooth/l2cap_sock.c:1319 l2cap_sock_release+0x16c/0x208 net/bluetooth/l2cap_sock.c:1492 __sock_release+0xa0/0x1d4 net/socket.c:710 sock_close+0x24/0x38 net/socket.c:1501 __fput+0x338/0x74c fs/file_table.c:512 ____fput+0x20/0x30 fs/file_table.c:540 task_work_run+0x1cc/0x25c 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:70 [inline] exit_to_user_mode_loop+0x10c/0x17c kernel/entry/common.c:101 __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] arm64_syscall_exit_to_user_mode arch/arm64/kernel/entry-common.c:88 [inline] el0_svc+0x18c/0x260 arch/arm64/kernel/entry-common.c:737 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 The buggy address belongs to the object at ffff0000c972e000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 392 bytes inside of freed 2048-byte region [ffff0000c972e000, ffff0000c972e800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff0000c972b000 pfn:0x109728 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 fffffdffc3191210 fffffdffc360b610 raw: ffff0000c972b000 0000000800080006 00000000f5000000 0000000000000000 head: 05ffc00000000240 ffff0000c0002000 fffffdffc3191210 fffffdffc360b610 head: ffff0000c972b000 0000000800080006 00000000f5000000 0000000000000000 head: 05ffc00000000003 fffffdffc325ca01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000c972e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000c972e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000c972e180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000c972e200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000c972e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Bluetooth: hci4: command 0x0c1a tx timeout Bluetooth: hci3: command tx timeout Bluetooth: hci3: command tx timeout Bluetooth: hci3: command tx timeout