==========[ 393.962929][ T5794] ================================================================== 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 ffff888039e3c778 by task syz-executor/5794 CPU: 0 UID: 0 PID: 5794 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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:132 [inline] __list_del_entry include/linux/list.h:223 [inline] list_del_init include/linux/list.h:295 [inline] bt_accept_unlink+0x39/0x240 net/bluetooth/af_bluetooth.c:259 l2cap_sock_teardown_cb+0x17e/0x460 net/bluetooth/l2cap_sock.c:1616 l2cap_chan_del+0xb5/0x5e0 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:2121 [inline] hci_conn_hash_flush+0x10d/0x230 net/bluetooth/hci_conn.c:2602 hci_dev_close_sync+0xaef/0x1330 net/bluetooth/hci_sync.c:5303 hci_dev_do_close net/bluetooth/hci_core.c:501 [inline] hci_unregister_dev+0x21a/0x510 net/bluetooth/hci_core.c:2715 vhci_release+0x155/0x1b0 drivers/bluetooth/hci_vhci.c:690 __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:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x125d/0x1310 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 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/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa3defd5117 Code: Unable to access opcode bytes at 0x7fa3defd50ed. RSP: 002b:00007ffe70d565b0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 000000000000030a RCX: 00007fa3defd5117 RDX: 0000000040000000 RSI: 00007ffe70d5661c RDI: 00000000ffffffff RBP: 00007ffe70d5661c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000125 R13: 0000555567c5f590 R14: 0000000000057e26 R15: 00007ffe70d56670 Allocated by task 5153: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x1ef/0x6c0 mm/slub.c:5755 kmalloc_noprof include/linux/slab.h:957 [inline] syslog_print+0xd2/0x590 kernel/printk/printk.c:1580 do_syslog+0x544/0x760 kernel/printk/printk.c:1758 __do_sys_syslog kernel/printk/printk.c:1850 [inline] __se_sys_syslog kernel/printk/printk.c:1848 [inline] __x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1848 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5153: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2530 [inline] slab_free mm/slub.c:6619 [inline] kfree+0x197/0x950 mm/slub.c:6826 syslog_print+0x515/0x590 kernel/printk/printk.c:1672 do_syslog+0x544/0x760 kernel/printk/printk.c:1758 __do_sys_syslog kernel/printk/printk.c:1850 [inline] __se_sys_syslog kernel/printk/printk.c:1848 [inline] __x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1848 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888039e3c000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1912 bytes inside of freed 2048-byte region [ffff888039e3c000, ffff888039e3c800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x39e38 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 ffff88813ff27000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813ff27000 dead000000000100 dead000000000122 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 0080000000000003 ffffea0000e78e01 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5796, tgid 5796 (syz-executor), ts 105259185409, free_ts 105125838476 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3046 [inline] allocate_slab+0x96/0x3a0 mm/slub.c:3219 new_slab mm/slub.c:3273 [inline] ___slab_alloc+0xb12/0x13f0 mm/slub.c:4643 __slab_alloc+0xc6/0x1f0 mm/slub.c:4762 __slab_alloc_node mm/slub.c:4838 [inline] slab_alloc_node mm/slub.c:5260 [inline] __do_kmalloc_node mm/slub.c:5633 [inline] __kmalloc_node_track_caller_noprof+0x2a8/0x7e0 mm/slub.c:5743 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:601 pskb_expand_head+0x18e/0x1150 net/core/skbuff.c:2241 netlink_trim+0x1d5/0x2e0 net/netlink/af_netlink.c:1301 netlink_broadcast_filtered+0xd6/0x1000 net/netlink/af_netlink.c:1514 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:2595 rtnl_notify net/core/rtnetlink.c:958 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:4429 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4445 [inline] rtnetlink_event+0x224/0x270 net/core/rtnetlink.c:7011 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] netif_change_name+0x5e5/0x990 net/core/dev.c:1489 page last free pid 5793 tgid 5793 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0xfb6/0x1140 mm/page_alloc.c:2906 __slab_free+0x2c6/0x370 mm/slub.c:5954 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4962 [inline] slab_alloc_node mm/slub.c:5272 [inline] kmem_cache_alloc_node_noprof+0x23b/0x6e0 mm/slub.c:5324 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660 netlink_sendmsg+0x5c6/0xb30 net/netlink/af_netlink.c:1871 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 __sys_sendto+0x3c7/0x520 net/socket.c:2244 __do_sys_sendto net/socket.c:2251 [inline] __se_sys_sendto net/socket.c:2247 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2247 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888039e3c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888039e3c680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888039e3c700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888039e3c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888039e3c800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================