syzbot

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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 ffff8880532dd778 by task syz-executor/17920

CPU: 0 UID: 0 PID: 17920 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:
 <TASK>
 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
 __do_sys_exit_group kernel/exit.c:1118 [inline]
 __se_sys_exit_group kernel/exit.c:1116 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116
 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
 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
RIP: 0033:0x7f52b72defc9
Code: Unable to access opcode bytes at 0x7f52b72def9f.
RSP: 002b:00007ffe24198c58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f52b7361def RCX: 00007f52b72defc9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000016 R08: 00007ffe241969f6 R09: 00007ffe24199f10
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe24199f10
R13: 00007f52b7361d7d R14: 0000555583dac4a8 R15: 00007ffe2419c0d0
 </TASK>

Allocated by task 21291:
 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]
 __do_kmalloc_node mm/slub.c:5642 [inline]
 __kmalloc_noprof+0x233/0x7d0 mm/slub.c:5654
 kmalloc_noprof include/linux/slab.h:961 [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:1897 [inline]
 l2cap_sock_create+0x147/0x300 net/bluetooth/l2cap_sock.c:1939
 bt_sock_create+0x163/0x240 net/bluetooth/af_bluetooth.c:135
 __sock_create+0x4b3/0x9f0 net/socket.c:1605
 sock_create net/socket.c:1663 [inline]
 __sys_socket_create net/socket.c:1700 [inline]
 __sys_socket+0xd7/0x1b0 net/socket.c:1747
 __do_sys_socket net/socket.c:1761 [inline]
 __se_sys_socket net/socket.c:1759 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1759
 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 21290:
 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:2539 [inline]
 slab_free mm/slub.c:6630 [inline]
 kfree+0x197/0x950 mm/slub.c:6837
 sk_prot_free net/core/sock.c:2278 [inline]
 __sk_destruct+0x4e4/0x670 net/core/sock.c:2373
 l2cap_sock_release+0x1b0/0x230 net/bluetooth/l2cap_sock.c:1438
 __sock_release net/socket.c:662 [inline]
 sock_close+0xc3/0x240 net/socket.c:1455
 __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+0xe9/0x130 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/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880532dd000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1912 bytes inside of
 freed 2048-byte region [ffff8880532dd000, ffff8880532dd800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x532d8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88813ff27000 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813ff27000 0000000000000000 dead000000000001
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 0080000000000003 ffffea00014cb601 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1508, tgid 1508 (kworker/u8:8), ts 1666350701923, free_ts 1660184902090
 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:3055 [inline]
 allocate_slab+0x96/0x350 mm/slub.c:3228
 new_slab mm/slub.c:3282 [inline]
 ___slab_alloc+0xb12/0x13f0 mm/slub.c:4651
 __slab_alloc+0xc6/0x1f0 mm/slub.c:4770
 __slab_alloc_node mm/slub.c:4846 [inline]
 slab_alloc_node mm/slub.c:5268 [inline]
 __do_kmalloc_node mm/slub.c:5641 [inline]
 __kmalloc_noprof+0x14b/0x7d0 mm/slub.c:5654
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 neigh_alloc net/core/neighbour.c:522 [inline]
 ___neigh_create+0x722/0x2360 net/core/neighbour.c:656
 ip6_finish_output2+0xa55/0x14c0 net/ipv6/ip6_output.c:128
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ndisc_send_skb+0xbce/0x1510 net/ipv6/ndisc.c:512
 addrconf_dad_completed+0x7c6/0xd70 net/ipv6/addrconf.c:4360
 addrconf_dad_work+0xd0d/0x15a0 include/linux/rwlock_rt.h:-1
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
page last free pid 19386 tgid 19386 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
 discard_slab mm/slub.c:3326 [inline]
 __put_partials+0x149/0x170 mm/slub.c:3872
 __slab_free+0x29e/0x370 mm/slub.c:5921
 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:4970 [inline]
 slab_alloc_node mm/slub.c:5280 [inline]
 __do_kmalloc_node mm/slub.c:5641 [inline]
 __kmalloc_noprof+0x1e1/0x7d0 mm/slub.c:5654
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x142/0x860 net/ipv6/route.c:3809
 ip6_route_add+0x49/0x1d0 net/ipv6/route.c:3938
 addrconf_prefix_route net/ipv6/addrconf.c:2488 [inline]
 inet6_addr_add+0x6a4/0xb40 net/ipv6/addrconf.c:3053
 inet6_rtm_newaddr+0x93d/0xd20 net/ipv6/addrconf.c:5059
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6951
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x846/0xa10 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896

Memory state around the buggy address:
 ffff8880532dd600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880532dd680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880532dd700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff8880532dd780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880532dd800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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