netlink: 8 bytes leftover after parsing attributes in process `syz-executor.1'.
==================================================================
BUG: KASAN: use-after-free in rxrpc_send_keepalive+0x83e/0x8e0 net/rxrpc/output.c:637
IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready
Read of size 8 at addr ffff88808af88918 by task kworker/0:3/7482

CPU: 0 PID: 7482 Comm: kworker/0:3 Not tainted 4.19.67 #41
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: krxrpcd rxrpc_peer_keepalive_worker
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 rxrpc_send_keepalive+0x83e/0x8e0 net/rxrpc/output.c:637
IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready
 rxrpc_peer_keepalive_dispatch net/rxrpc/peer_event.c:366 [inline]
 rxrpc_peer_keepalive_worker+0x7be/0xd02 net/rxrpc/peer_event.c:427
 process_one_work+0x989/0x1750 kernel/workqueue.c:2153
 worker_thread+0x98/0xe40 kernel/workqueue.c:2296
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 15008:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
 kmem_cache_alloc_trace+0x152/0x760 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 ipv6_add_dev net/ipv6/addrconf.c:376 [inline]
 ipv6_add_dev+0xd1/0x10a0 net/ipv6/addrconf.c:366
 addrconf_notify+0x938/0x22e0 net/ipv6/addrconf.c:3435
 notifier_call_chain+0xc2/0x230 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x2e/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x3f/0x90 net/core/dev.c:1747
 call_netdevice_notifiers net/core/dev.c:1765 [inline]
 register_netdevice+0xa4d/0xff0 net/core/dev.c:8561
 register_netdev+0x30/0x50 net/core/dev.c:8650
 br_add_bridge+0xa4/0x100 net/bridge/br_if.c:461
 br_ioctl_deviceless_stub+0x71a/0x7b0 net/bridge/br_ioctl.c:378
 sock_ioctl+0x2ec/0x610 net/socket.c:1041
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 9:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcf/0x220 mm/slab.c:3822
 in6_dev_finish_destroy_rcu+0x8a/0xb0 net/ipv6/addrconf_core.c:209
 __rcu_reclaim kernel/rcu/rcu.h:236 [inline]
 rcu_do_batch kernel/rcu/tree.c:2584 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2864 [inline]
 rcu_process_callbacks+0xba0/0x1a30 kernel/rcu/tree.c:2881
 __do_softirq+0x25c/0x921 kernel/softirq.c:292

The buggy address belongs to the object at ffff88808af88900
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 24 bytes inside of
 1024-byte region [ffff88808af88900, ffff88808af88d00)
The buggy address belongs to the page:
page:ffffea00022be200 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000008100(slab|head)
raw: 01fffc0000008100 ffffea000266f388 ffffea0002293508 ffff88812c3f0ac0
raw: 0000000000000000 ffff88808af88000 0000000100000007 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808af88800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808af88880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808af88900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88808af88980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808af88a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================