================================================================== BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x92/0x190 lib/list_debug.c:62 Read of size 8 at addr ffff888030c85760 by task syz.1.588/7504 CPU: 1 UID: 0 PID: 7504 Comm: syz.1.588 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS G[ 247.425380][ T7504] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __list_del_entry_valid_or_report+0x92/0x190 lib/list_debug.c:62 __list_del_entry_valid include/linux/list.h:124 [inline] __list_del_entry include/linux/list.h:215 [inline] list_del_init include/linux/list.h:287 [inline] bt_accept_unlink+0x39/0x240 net/bluetooth/af_bluetooth.c:259 l2cap_sock_teardown_cb+0x17e/0x460 net/bluetooth/l2cap_sock.c:1613 l2cap_chan_del+0xb2/0x5e0 net/bluetooth/l2cap_core.c:655 l2cap_conn_del+0x388/0x680 net/bluetooth/l2cap_core.c:1787 hci_disconn_cfm include/net/bluetooth/hci_core.h:2097 [inline] hci_conn_hash_flush+0x10d/0x230 net/bluetooth/hci_conn.c:2599 hci_dev_close_sync+0xaef/0x1330 net/bluetooth/hci_sync.c:5294 hci_dev_do_close net/bluetooth/hci_core.c:501 [inline] hci_unregister_dev+0x21a/0x510 net/bluetooth/hci_core.c:2715 vhci_release+0x83/0xe0 drivers/bluetooth/hci_vhci.c:665 __fput+0x45b/0xa80 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x125e/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f170d5e14a5 Code: Unable to access opcode bytes at 0x7f170d5e147b. RSP: 002b:00007f170b80df80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007f170d7e5fa0 RCX: 00007f170d5e14a5 RDX: 00007f170b80dfc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f170d631e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007f170d7e6038 R14: 00007f170d7e5fa0 R15: 00007ffd5da7feb8 Allocated by task 8784: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4365 [inline] __kmalloc_noprof+0x1ef/0x430 mm/slub.c:4377 kmalloc_noprof include/linux/slab.h:909 [inline] sk_prot_alloc+0xe7/0x220 net/core/sock.c:2239 sk_alloc+0x3a/0x370 net/core/sock.c:2295 bt_sock_alloc+0x3b/0x310 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1894 [inline] l2cap_sock_create+0x147/0x300 net/bluetooth/l2cap_sock.c:1936 bt_sock_create+0x163/0x240 net/bluetooth/af_bluetooth.c:135 __sock_create+0x4b3/0x9f0 net/socket.c:1589 sock_create net/socket.c:1647 [inline] __sys_socket_create net/socket.c:1684 [inline] __sys_socket+0xd7/0x1b0 net/socket.c:1731 __do_sys_socket net/socket.c:1745 [inline] __se_sys_socket net/socket.c:1743 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1743 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8784: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x195/0x550 mm/slub.c:4879 sk_prot_free net/core/sock.c:2278 [inline] __sk_destruct+0x4e4/0x670 net/core/sock.c:2373 l2cap_sock_release+0x17d/0x200 net/bluetooth/l2cap_sock.c:1435 __sock_release net/socket.c:649 [inline] sock_close+0xc0/0x240 net/socket.c:1439 __fput+0x45b/0xa80 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888030c85000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1888 bytes inside of freed 2048-byte region [ffff888030c85000, ffff888030c85800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x30c80 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff888019842000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 0080000000000040 ffff888019842000 dead000000000100 dead000000000122 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 0080000000000003 ffffea0000c32001 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 17609428260, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x2119/0x21b0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2655 new_slab mm/slub.c:2709 [inline] ___slab_alloc+0x8d1/0xdd0 mm/slub.c:3891 __slab_alloc mm/slub.c:3981 [inline] __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __kmalloc_cache_noprof+0xe6/0x320 mm/slub.c:4391 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] device_create_groups_vargs drivers/base/core.c:4353 [inline] device_create_with_groups+0x12f/0x2f0 drivers/base/core.c:4451 misc_register+0x2c8/0x4f0 drivers/char/misc.c:246 vsock_init+0x10c/0x1a0 net/vmw_vsock/af_vsock.c:2652 do_one_initcall+0x233/0x820 init/main.c:1269 do_initcall_level+0x104/0x190 init/main.c:1331 do_initcalls+0x59/0xa0 init/main.c:1347 kernel_init_freeable+0x334/0x4b0 init/main.c:1579 kernel_init+0x1d/0x1d0 init/main.c:1469 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 page_owner free stack trace missing Memory state around the buggy address: ffff888030c85600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888030c85680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888030c85700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888030c85780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888030c85800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================