netlink: 20 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'.
netlink: 20 bytes leftover after parsing attributes in process `syz-executor.3'.
==================================================================
BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:704 [inline]
BUG: KASAN: use-after-free in qdisc_class_hash_insert+0x200/0x210 net/sched/sch_api.c:694
Write of size 8 at addr ffff8880a840cd90 by task syz-executor.1/21776

CPU: 1 PID: 21776 Comm: syz-executor.1 Not tainted 4.14.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2b9 mm/kasan/report.c:393
 hlist_add_head include/linux/list.h:704 [inline]
 qdisc_class_hash_insert+0x200/0x210 net/sched/sch_api.c:694
 qfq_change_class+0xa13/0x107a net/sched/sch_qfq.c:500
 tc_ctl_tclass+0x3e2/0xa00 net/sched/sch_api.c:1848
 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4315
 netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2433
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x64a/0xbb0 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45cb29
RSP: 002b:00007feff5ce2c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000005026e0 RCX: 000000000045cb29
RDX: 0000000000000000 RSI: 0000000020000280 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 0000000000000a42 R14: 00000000004cd2b2 R15: 00007feff5ce36d4

Allocated by task 21751:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551
 kmem_cache_alloc_trace+0x14d/0x3f0 mm/slab.c:3618
 kmalloc include/linux/slab.h:488 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 qfq_change_class+0x7d2/0x107a net/sched/sch_qfq.c:475
 tc_ctl_tclass+0x3e2/0xa00 net/sched/sch_api.c:1848
 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4315
 netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2433
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x64a/0xbb0 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 21751:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xaf/0x190 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcb/0x260 mm/slab.c:3815
 qfq_change_class+0xd86/0x107a net/sched/sch_qfq.c:529
 tc_ctl_tclass+0x3e2/0xa00 net/sched/sch_api.c:1848
 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4315
 netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2433
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x64a/0xbb0 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

The buggy address belongs to the object at ffff8880a840cd80
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 16 bytes inside of
 128-byte region [ffff8880a840cd80, ffff8880a840ce00)
The buggy address belongs to the page:
page:ffffea0002a10300 count:1 mapcount:0 mapping:ffff8880a840c000 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff8880a840c000 0000000000000000 0000000100000015
raw: ffffea0002a1ac20 ffffea000138b560 ffff8880aa800640 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a840cc80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff8880a840cd00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff8880a840cd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff8880a840ce00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff8880a840ce80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================