================================================================== BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x8c/0x1b4 lib/list_debug.c:62 Read of size 8 at addr ffff0000f6548578 by task syz-executor/6742 CPU: 0 UID: 0 PID: 6742 Comm: syz-executor Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 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+0xa8/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0xb0/0x110 mm/kasan/report.c:595 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __list_del_entry_valid_or_report+0x8c/0x1b4 lib/list_debug.c:62 __list_del_entry_valid include/linux/list.h:132 [inline] __list_del_entry include/linux/list.h:223 [inline] list_del_init include/linux/list.h:295 [inline] bt_accept_unlink+0x40/0x26c net/bluetooth/af_bluetooth.c:259 l2cap_sock_teardown_cb+0x148/0x388 net/bluetooth/l2cap_sock.c:1616 l2cap_chan_del+0xb8/0x498 net/bluetooth/l2cap_core.c:656 l2cap_conn_del+0x2b8/0x53c net/bluetooth/l2cap_core.c:1788 l2cap_disconn_cfm+0x90/0x104 net/bluetooth/l2cap_core.c:7326 hci_disconn_cfm include/net/bluetooth/hci_core.h:2146 [inline] hci_conn_hash_flush+0x108/0x23c net/bluetooth/hci_conn.c:2637 hci_dev_close_sync+0x65c/0xfd0 net/bluetooth/hci_sync.c:5326 hci_dev_do_close net/bluetooth/hci_core.c:501 [inline] hci_unregister_dev+0x204/0x52c net/bluetooth/hci_core.c:2715 vhci_release+0x12c/0x17c drivers/bluetooth/hci_vhci.c:690 __fput+0x340/0x75c fs/file_table.c:468 ____fput+0x20/0x58 fs/file_table.c:496 task_work_run+0x1dc/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x52c/0x1a1c kernel/exit.c:971 do_group_exit+0x194/0x22c kernel/exit.c:1112 get_signal+0x11dc/0x12f8 kernel/signal.c:3034 arch_do_signal_or_restart+0x268/0x46d4 arch/arm64/kernel/signal.c:1619 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x88/0x18c kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] exit_to_user_mode_prepare_legacy include/linux/irq-entry-common.h:242 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:81 [inline] el0_svc+0x17c/0x26c arch/arm64/kernel/entry-common.c:725 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Allocated by task 12523: 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:5657 [inline] __kmalloc_node_track_caller_noprof+0x510/0x778 mm/slub.c:5764 kmalloc_reserve+0x124/0x268 net/core/skbuff.c:608 pskb_expand_head+0x150/0xe80 net/core/skbuff.c:2282 netlink_trim+0x198/0x2c0 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0xc4/0xde8 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+0xfc/0x1e0 net/netlink/af_netlink.c:2593 rtnl_notify net/core/rtnetlink.c:958 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:4436 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4452 [inline] rtmsg_ifinfo+0x138/0x188 net/core/rtnetlink.c:4458 __dev_notify_flags+0xec/0x464 net/core/dev.c:9771 netif_change_flags+0xd0/0x15c net/core/dev.c:9804 do_setlink+0xa58/0x3658 net/core/rtnetlink.c:3158 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x1104/0x15e8 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x664/0x97c net/core/rtnetlink.c:6958 netlink_rcv_skb+0x220/0x3fc net/netlink/af_netlink.c:2550 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6985 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x694/0x8c4 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x648/0x930 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x36c/0x4f4 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __arm64_sys_sendto+0xd8/0xf8 net/socket.c:2209 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Freed by task 12523: 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:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x1c4/0x5fc mm/slub.c:6878 skb_kfree_head net/core/skbuff.c:1068 [inline] skb_free_head+0xe4/0x198 net/core/skbuff.c:1080 skb_release_data+0x4d4/0x664 net/core/skbuff.c:1107 skb_release_all net/core/skbuff.c:1182 [inline] __kfree_skb net/core/skbuff.c:1196 [inline] consume_skb+0xb0/0x130 net/core/skbuff.c:1428 netlink_broadcast_filtered+0xc60/0xde8 net/netlink/af_netlink.c:1535 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xfc/0x1e0 net/netlink/af_netlink.c:2593 rtnl_notify net/core/rtnetlink.c:958 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:4436 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4452 [inline] rtmsg_ifinfo+0x138/0x188 net/core/rtnetlink.c:4458 __dev_notify_flags+0xec/0x464 net/core/dev.c:9771 netif_change_flags+0xd0/0x15c net/core/dev.c:9804 do_setlink+0xa58/0x3658 net/core/rtnetlink.c:3158 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x1104/0x15e8 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x664/0x97c net/core/rtnetlink.c:6958 netlink_rcv_skb+0x220/0x3fc net/netlink/af_netlink.c:2550 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6985 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x694/0x8c4 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x648/0x930 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x36c/0x4f4 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __arm64_sys_sendto+0xd8/0xf8 net/socket.c:2209 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 The buggy address belongs to the object at ffff0000f6548000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1400 bytes inside of freed 2048-byte region [ffff0000f6548000, ffff0000f6548800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x136548 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000040 ffff0000c0002000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 05ffc00000000040 ffff0000c0002000 dead000000000100 dead000000000122 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 05ffc00000000003 fffffdffc3d95201 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f6548400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000f6548480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000f6548500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000f6548580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000f6548600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== slab kmalloc-2k start ffff0000f6548000 pointer offset 1400 size 2048 list_del corruption. prev->next should be ffff0000dd1c9578, but was 0000000000000000. (prev=ffff0000f6548578) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:64! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP Modules linked in: CPU: 1 UID: 0 PID: 6742 Comm: syz-executor Tainted: G B syzkaller #0 PREEMPT Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 pstate: 63400005 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : __list_del_entry_valid_or_report+0x17c/0x1b4 lib/list_debug.c:62 lr : __list_del_entry_valid_or_report+0x17c/0x1b4 lib/list_debug.c:62 sp : ffff8000a0757370 x29: ffff8000a0757370 x28: ffff0000c63172c0 x27: dfff800000000000 x26: ffff0000dd1cc00c x25: 1fffe0001ba39802 x24: dfff800000000000 x23: 1fffe0001eca90af x22: dfff800000000000 x21: ffff0000f6548578 x20: ffff0000f6548578 x19: ffff0000dd1c9578 x18: 1fffe00033781890 x17: 20747562202c3837 x16: ffff800082e5e68c x15: 0000000000000001 x14: 1ffff000140eadac x13: 0000000000000000 x12: 0000000000000000 x11: 00000000000142bb x10: 0000000000ff0100 x9 : a5faaa464cdb0f00 x8 : a5faaa464cdb0f00 x7 : 000000000027ad20 x6 : ffff8000805761f8 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000002 x2 : 0000000000000001 x1 : 0000000100000000 x0 : 000000000000006d Call trace: __list_del_entry_valid_or_report+0x17c/0x1b4 lib/list_debug.c:62 (P) __list_del_entry_valid include/linux/list.h:132 [inline] __list_del_entry include/linux/list.h:223 [inline] list_del_init include/linux/list.h:295 [inline] bt_accept_unlink+0x40/0x26c net/bluetooth/af_bluetooth.c:259 l2cap_sock_teardown_cb+0x148/0x388 net/bluetooth/l2cap_sock.c:1616 l2cap_chan_del+0xb8/0x498 net/bluetooth/l2cap_core.c:656 l2cap_conn_del+0x2b8/0x53c net/bluetooth/l2cap_core.c:1788 l2cap_disconn_cfm+0x90/0x104 net/bluetooth/l2cap_core.c:7326 hci_disconn_cfm include/net/bluetooth/hci_core.h:2146 [inline] hci_conn_hash_flush+0x108/0x23c net/bluetooth/hci_conn.c:2637 hci_dev_close_sync+0x65c/0xfd0 net/bluetooth/hci_sync.c:5326 hci_dev_do_close net/bluetooth/hci_core.c:501 [inline] hci_unregister_dev+0x204/0x52c net/bluetooth/hci_core.c:2715 vhci_release+0x12c/0x17c drivers/bluetooth/hci_vhci.c:690 __fput+0x340/0x75c fs/file_table.c:468 ____fput+0x20/0x58 fs/file_table.c:496 task_work_run+0x1dc/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x52c/0x1a1c kernel/exit.c:971 do_group_exit+0x194/0x22c kernel/exit.c:1112 get_signal+0x11dc/0x12f8 kernel/signal.c:3034 arch_do_signal_or_restart+0x268/0x46d4 arch/arm64/kernel/signal.c:1619 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x88/0x18c kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] exit_to_user_mode_prepare_legacy include/linux/irq-entry-common.h:242 [inline] arm64_exit_to_user_mode arch/arm64/kernel/entry-common.c:81 [inline] el0_svc+0x17c/0x26c arch/arm64/kernel/entry-common.c:725 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596 Code: 91058000 aa1303e1 aa1503e3 974a97c3 (d4210000) ---[ end trace 0000000000000000 ]---