================================================================== 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 ffff88805d23a558 by task syz.5.1166/10726 CPU: 1 UID: 0 PID: 10726 Comm: syz.5.1166 Not tainted 6.16.0-rc7-syzkaller-00105-g2942242dde89 #0 PREEMPT(full) 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+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:2074 [inline] hci_conn_hash_flush+0x10d/0x230 net/bluetooth/hci_conn.c:2560 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:2717 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:665 __fput+0x449/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x22e0 kernel/exit.c:964 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105 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:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3c03d8e9a9 Code: Unable to access opcode bytes at 0x7f3c03d8e97f. RSP: 002b:00007f3c04c28038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: 0000000000018ff8 RBX: 00007f3c03fb5fa0 RCX: 00007f3c03d8e9a9 RDX: 0000000000018ff8 RSI: 0000200000019680 RDI: 000000000000000a RBP: 00007f3c03e10d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3c03fb5fa0 R15: 00007ffd152c3a58 Allocated by task 10560: 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:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4328 [inline] __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] sk_prot_alloc+0xe7/0x220 net/core/sock.c:2247 sk_alloc+0x3a/0x370 net/core/sock.c:2303 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+0x4b0/0x9f0 net/socket.c:1541 sock_create net/socket.c:1599 [inline] __sys_socket_create net/socket.c:1636 [inline] __sys_socket+0xd7/0x1b0 net/socket.c:1683 __do_sys_socket net/socket.c:1697 [inline] __se_sys_socket net/socket.c:1695 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1695 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 10559: 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:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 sk_prot_free net/core/sock.c:2286 [inline] __sk_destruct+0x4e1/0x660 net/core/sock.c:2381 l2cap_sock_release+0x158/0x1d0 net/bluetooth/l2cap_sock.c:1435 __sock_release net/socket.c:647 [inline] sock_close+0xc3/0x240 net/socket.c:1391 __fput+0x449/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 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:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [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 ffff88805d23a000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1368 bytes inside of freed 2048-byte region [ffff88805d23a000, ffff88805d23a800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805d239000 pfn:0x5d238 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801a442000 ffffea00015f4e10 ffffea0001abec10 raw: ffff88805d239000 0000000000080002 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801a442000 ffffea00015f4e10 ffffea0001abec10 head: ffff88805d239000 0000000000080002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001748e01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7095, tgid 7095 (syz-executor), ts 193036401861, free_ts 192979559755 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x21d5/0x22b0 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2619 new_slab mm/slub.c:2673 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859 __slab_alloc mm/slub.c:3949 [inline] __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_track_caller_noprof+0x2f8/0x4e0 mm/slub.c:4347 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+0x80/0x1140 net/netlink/af_netlink.c:1514 nlmsg_multicast_filtered include/net/netlink.h:1151 [inline] nlmsg_multicast include/net/netlink.h:1170 [inline] nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2595 __dev_notify_flags+0xf4/0x2e0 net/core/dev.c:9493 rtnl_configure_link+0x22c/0x350 net/core/rtnetlink.c:3589 veth_newlink+0x4a5/0xa50 drivers/net/veth.c:1865 rtnl_newlink_create+0x30d/0xb00 net/core/rtnetlink.c:3823 page last free pid 7095 tgid 7095 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc65/0xe60 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x161/0x1c0 mm/slub.c:3186 put_cpu_partial+0x17c/0x250 mm/slub.c:3261 __slab_free+0x2f7/0x400 mm/slub.c:4513 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:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4249 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1336 [inline] nlmsg_new include/net/netlink.h:1041 [inline] netlink_ack+0x146/0xa50 net/netlink/af_netlink.c:2489 netlink_rcv_skb+0x28c/0x470 net/netlink/af_netlink.c:2558 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:727 __sys_sendto+0x3bd/0x520 net/socket.c:2180 __do_sys_sendto net/socket.c:2187 [inline] __se_sys_sendto net/socket.c:2183 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2183 Memory state around the buggy address: ffff88805d23a400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805d23a480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805d23a500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805d23a580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805d23a600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================