==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:774 [inline]
BUG: KASAN: slab-use-after-free in sco_conn_del+0xb9/0x2d0 net/bluetooth/sco.c:195
Write of size 4 at addr ffff88804a7d9080 by task syz-executor.0/29000

CPU: 2 PID: 29000 Comm: syz-executor.0 Not tainted 6.8.0-syzkaller-11767-g23956900041d #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:774 [inline]
 sco_conn_del+0xb9/0x2d0 net/bluetooth/sco.c:195
 sco_disconn_cfm+0x76/0xb0 net/bluetooth/sco.c:1372
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2022 [inline]
 hci_conn_hash_flush+0x114/0x260 net/bluetooth/hci_conn.c:2566
 hci_dev_close_sync+0x59b/0x11e0 net/bluetooth/hci_sync.c:5153
 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:554
 hci_unregister_dev+0x1eb/0x600 net/bluetooth/hci_core.c:2773
 vhci_release+0x7f/0x100 drivers/bluetooth/hci_vhci.c:674
 __fput+0x270/0xb80 fs/file_table.c:422
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa7d/0x2c10 kernel/exit.c:878
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
 get_signal+0x2616/0x2710 kernel/signal.c:2911
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:105 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline]
 syscall_exit_to_user_mode+0x14a/0x2a0 kernel/entry/common.c:212
 do_syscall_64+0xe2/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fc499e7ca4c
Code: Unable to access opcode bytes at 0x7fc499e7ca22.
RSP: 002b:00007ffe05adfdb0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 00007fc499e7ca4c
RDX: 0000000000000040 RSI: 00007fc499fa8020 RDI: 00000000000000f9
RBP: 00007ffe05adfe3c R08: 0000000000000000 R09: 0079746972756365
R10: 00007ffe05adf770 R11: 0000000000000246 R12: 0000000000000032
R13: 00000000000683e3 R14: 00000000000683d8 R15: 0000000000000004
 </TASK>

Allocated by task 9:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slub.c:3966 [inline]
 __kmalloc_node_track_caller+0x220/0x470 mm/slub.c:3986
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:599
 __alloc_skb+0x164/0x380 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1318 [inline]
 alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6504
 sock_alloc_send_pskb+0x7f1/0x980 net/core/sock.c:2795
 sock_alloc_send_skb include/net/sock.h:1835 [inline]
 mld_newpack.isra.0+0x1ed/0x790 net/ipv6/mcast.c:1746
 add_grhead+0x299/0x340 net/ipv6/mcast.c:1849
 add_grec+0x111e/0x1670 net/ipv6/mcast.c:1987
 mld_send_initial_cr.part.0+0xe2/0x260 net/ipv6/mcast.c:2233
 mld_send_initial_cr net/ipv6/mcast.c:2224 [inline]
 mld_dad_work+0x51/0x2f0 net/ipv6/mcast.c:2259
 process_one_work+0x9a9/0x1ac0 kernel/workqueue.c:3254
 process_scheduled_works kernel/workqueue.c:3335 [inline]
 worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416
 kthread+0x2c1/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

Freed by task 9:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:240 [inline]
 __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2106 [inline]
 slab_free mm/slub.c:4280 [inline]
 kfree+0x129/0x390 mm/slub.c:4390
 skb_kfree_head net/core/skbuff.c:1096 [inline]
 skb_free_head+0x110/0x1e0 net/core/skbuff.c:1108
 skb_release_data+0x76c/0x990 net/core/skbuff.c:1136
 skb_release_all net/core/skbuff.c:1202 [inline]
 __kfree_skb net/core/skbuff.c:1216 [inline]
 kfree_skb_reason+0x12d/0x210 net/core/skbuff.c:1252
 kfree_skb include/linux/skbuff.h:1267 [inline]
 ip6_mc_input+0x7ad/0xfd0 net/ipv6/ip6_input.c:589
 dst_input include/net/dst.h:460 [inline]
 dst_input include/net/dst.h:458 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 ipv6_rcv+0x45a/0x680 net/ipv6/ip6_input.c:310
 __netif_receive_skb_one_core+0x12e/0x1e0 net/core/dev.c:5538
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5652
 process_backlog+0x12f/0x6f0 net/core/dev.c:5981
 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:6632
 napi_poll net/core/dev.c:6701 [inline]
 net_rx_action+0x9ad/0xf10 net/core/dev.c:6813
 __do_softirq+0x218/0x922 kernel/softirq.c:554

The buggy address belongs to the object at ffff88804a7d9000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff88804a7d9000, ffff88804a7d9800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4a7d8
head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000840 ffff888015042f00 ffffea0001198000 dead000000000002
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
head: 00fff80000000840 ffff888015042f00 ffffea0001198000 dead000000000002
head: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
head: 00fff80000000003 ffffea000129f601 ffffea000129f648 00000000ffffffff
head: 0000000800000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 23668, tgid 23668 (syz-executor.1), ts 335004410256, free_ts 334938776008
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317
 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page mm/slub.c:2175 [inline]
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0xcc/0x3a0 mm/slub.c:2391
 ___slab_alloc+0x66d/0x1790 mm/slub.c:3525
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 __do_kmalloc_node mm/slub.c:3965 [inline]
 __kmalloc_node_track_caller+0x367/0x470 mm/slub.c:3986
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:599
 __alloc_skb+0x164/0x380 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1318 [inline]
 nlmsg_new include/net/netlink.h:1010 [inline]
 inet6_ifinfo_notify+0x77/0x150 net/ipv6/addrconf.c:6158
 addrconf_notify+0x827/0x19e0 net/ipv6/addrconf.c:3760
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1950
 call_netdevice_notifiers_extack net/core/dev.c:1988 [inline]
 call_netdevice_notifiers net/core/dev.c:2002 [inline]
 __dev_notify_flags+0x12d/0x2e0 net/core/dev.c:8722
 dev_change_flags+0x10c/0x160 net/core/dev.c:8760
 do_setlink+0x1a3b/0x3fe0 net/core/rtnetlink.c:2884
page last free pid 24061 tgid 24060 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347
 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc_node+0x177/0x340 mm/slub.c:3888
 __alloc_skb+0x2b1/0x380 net/core/skbuff.c:658
 alloc_skb include/linux/skbuff.h:1318 [inline]
 netlink_alloc_large_skb+0x69/0x130 net/netlink/af_netlink.c:1210
 netlink_sendmsg+0x689/0xd70 net/netlink/af_netlink.c:1880
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0xab5/0xc90 net/socket.c:2584
 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2638
 __sys_sendmsg+0x117/0x1f0 net/socket.c:2667
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Memory state around the buggy address:
 ffff88804a7d8f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88804a7d9000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88804a7d9080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88804a7d9100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804a7d9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================