GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
==================================================================
BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:182 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:680 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock+0xa65/0xb90 kernel/locking/mutex.c:746
Read of size 8 at addr ffff888013736b20 by task kworker/2:4/5992

CPU: 2 UID: 0 PID: 5992 Comm: kworker/2:4 Not tainted 6.15.0-rc1-syzkaller-00065-g3b07108ada81 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: events l2cap_chan_timeout
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 __mutex_waiter_is_first kernel/locking/mutex.c:182 [inline]
 __mutex_lock_common kernel/locking/mutex.c:680 [inline]
 __mutex_lock+0xa65/0xb90 kernel/locking/mutex.c:746
 l2cap_chan_timeout+0x6d/0x310 net/bluetooth/l2cap_core.c:417
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 9903:
 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:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 l2cap_conn_add.part.0+0x60/0xa60 net/bluetooth/l2cap_core.c:6860
 l2cap_conn_add include/net/bluetooth/hci_core.h:1639 [inline]
 l2cap_chan_connect+0x15e5/0x2020 net/bluetooth/l2cap_core.c:7051
 l2cap_sock_connect+0x3b7/0x740 net/bluetooth/l2cap_sock.c:256
 kernel_connect+0x104/0x180 net/socket.c:3608
 rfcomm_session_create net/bluetooth/rfcomm/core.c:811 [inline]
 __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline]
 rfcomm_dlc_open+0x821/0xaa0 net/bluetooth/rfcomm/core.c:431
 rfcomm_sock_connect+0x423/0x670 net/bluetooth/rfcomm/sock.c:409
 __sys_connect_file+0x13e/0x1a0 net/socket.c:2038
 __sys_connect+0x14d/0x170 net/socket.c:2057
 __do_sys_connect net/socket.c:2063 [inline]
 __se_sys_connect net/socket.c:2060 [inline]
 __ia32_sys_connect+0x71/0xb0 net/socket.c:2060
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Freed by task 10025:
 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:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2389 [inline]
 slab_free mm/slub.c:4646 [inline]
 kfree+0x2b6/0x4d0 mm/slub.c:4845
 l2cap_conn_free net/bluetooth/l2cap_core.c:1810 [inline]
 kref_put include/linux/kref.h:65 [inline]
 l2cap_conn_put net/bluetooth/l2cap_core.c:1822 [inline]
 l2cap_conn_del+0x59c/0x730 net/bluetooth/l2cap_core.c:1802
 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7299 [inline]
 l2cap_disconn_cfm+0x96/0xd0 net/bluetooth/l2cap_core.c:7292
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2069 [inline]
 hci_conn_hash_flush+0x10b/0x260 net/bluetooth/hci_conn.c:2701
 hci_dev_do_reset net/bluetooth/hci_core.c:548 [inline]
 hci_dev_reset+0x1ee/0x530 net/bluetooth/hci_core.c:592
 hci_sock_ioctl+0x493/0x7d0 net/bluetooth/hci_sock.c:1133
 hci_sock_compat_ioctl+0x43/0x80 net/bluetooth/hci_sock.c:1174
 compat_sock_ioctl+0x173/0x7c0 net/socket.c:3500
 __do_compat_sys_ioctl+0x1cb/0x2c0 fs/ioctl.c:1004
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff888013736800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 800 bytes inside of
 freed 1024-byte region [ffff888013736800, ffff888013736c00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13730
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b442dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b442dc0 dead000000000100 dead000000000122
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea00004dcc01 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 0, tgid 0 (swapper/2), ts 81300656050, free_ts 81299510050
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1717
 prep_new_page mm/page_alloc.c:1725 [inline]
 get_page_from_freelist+0x1193/0x39b0 mm/page_alloc.c:3652
 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4934
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2459 [inline]
 allocate_slab mm/slub.c:2623 [inline]
 new_slab+0x23c/0x330 mm/slub.c:2676
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3862
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3952
 __slab_alloc_node mm/slub.c:4027 [inline]
 slab_alloc_node mm/slub.c:4188 [inline]
 __do_kmalloc_node mm/slub.c:4330 [inline]
 __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4343
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 neigh_alloc net/core/neighbour.c:473 [inline]
 ___neigh_create+0x14e6/0x28c0 net/core/neighbour.c:607
 neigh_create include/net/neighbour.h:342 [inline]
 __neigh_lookup include/net/neighbour.h:550 [inline]
 __neigh_lookup include/net/neighbour.h:543 [inline]
 ndisc_router_discovery+0x1413/0x3550 net/ipv6/ndisc.c:1487
 ndisc_rcv+0x3fa/0x620 net/ipv6/ndisc.c:1874
 icmpv6_rcv+0x17c6/0x1c50 net/ipv6/icmp.c:988
 ip6_protocol_deliver_rcu+0xf86/0x1520 net/ipv6/ip6_input.c:436
 ip6_input_finish+0x102/0x180 net/ipv6/ip6_input.c:480
 NF_HOOK include/linux/netfilter.h:314 [inline]
 NF_HOOK include/linux/netfilter.h:308 [inline]
 ip6_input+0x105/0x2f0 net/ipv6/ip6_input.c:491
 ip6_mc_input+0x465/0xfd0 net/ipv6/ip6_input.c:588
page last free pid 1137 tgid 1137 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2680
 discard_slab mm/slub.c:2720 [inline]
 __put_partials+0x16d/0x1c0 mm/slub.c:3189
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4151 [inline]
 slab_alloc_node mm/slub.c:4200 [inline]
 kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4252
 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:658
 alloc_skb include/linux/skbuff.h:1340 [inline]
 mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1788
 add_grhead+0x299/0x340 net/ipv6/mcast.c:1899
 add_grec+0x112a/0x1680 net/ipv6/mcast.c:2037
 mld_send_initial_cr.part.0+0xe2/0x260 net/ipv6/mcast.c:2282
 mld_send_initial_cr include/linux/refcount.h:291 [inline]
 ipv6_mc_dad_complete+0x22c/0x2b0 net/ipv6/mcast.c:2293
 addrconf_dad_completed+0xbb8/0x10d0 net/ipv6/addrconf.c:4340
 addrconf_dad_work+0x84d/0x14e0 net/ipv6/addrconf.c:4268
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400

Memory state around the buggy address:
 ffff888013736a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888013736a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888013736b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888013736b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888013736c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================