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BUG: KASAN: use-after-free in __write_once_size include/linux/compiler.h:226 [inline]
BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:857 [inline]
BUG: KASAN: use-after-free in qdisc_class_hash_insert+0x25e/0x270 net/sched/sch_api.c:727
Write of size 8 at addr ffff8880a7426010 by task syz-executor.4/13677

CPU: 0 PID: 13677 Comm: syz-executor.4 Not tainted 5.6.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:374
 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:503
 kasan_report+0x33/0x50 mm/kasan/common.c:648
 __write_once_size include/linux/compiler.h:226 [inline]
 hlist_add_head include/linux/list.h:857 [inline]
 qdisc_class_hash_insert+0x25e/0x270 net/sched/sch_api.c:727
 qfq_change_class+0x9da/0x1444 net/sched/sch_qfq.c:489
 tc_ctl_tclass+0x52a/0xe60 net/sched/sch_api.c:2108
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5454
 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6bf/0x7e0 net/socket.c:2362
 ___sys_sendmsg+0x100/0x170 net/socket.c:2416
 __sys_sendmsg+0xec/0x1b0 net/socket.c:2449
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45c889
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fd6e2ba0c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd6e2ba16d4 RCX: 000000000045c889
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 000000000076bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 00000000000009fd R14: 00000000004ccb8d R15: 0000000000000006

Allocated by task 13643:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:518 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:491
 kmem_cache_alloc_trace+0x153/0x7d0 mm/slab.c:3551
 kmalloc include/linux/slab.h:555 [inline]
 kzalloc include/linux/slab.h:669 [inline]
 qfq_change_class+0x756/0x1444 net/sched/sch_qfq.c:464
 tc_ctl_tclass+0x52a/0xe60 net/sched/sch_api.c:2108
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5454
 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6bf/0x7e0 net/socket.c:2362
 ___sys_sendmsg+0x100/0x170 net/socket.c:2416
 __sys_sendmsg+0xec/0x1b0 net/socket.c:2449
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 13643:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:340 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:479
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x109/0x2b0 mm/slab.c:3757
 qfq_change_class+0xeec/0x1444 net/sched/sch_qfq.c:518
 tc_ctl_tclass+0x52a/0xe60 net/sched/sch_api.c:2108
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5454
 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6bf/0x7e0 net/socket.c:2362
 ___sys_sendmsg+0x100/0x170 net/socket.c:2416
 __sys_sendmsg+0xec/0x1b0 net/socket.c:2449
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

The buggy address belongs to the object at ffff8880a7426000
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 16 bytes inside of
 128-byte region [ffff8880a7426000, ffff8880a7426080)
The buggy address belongs to the page:
page:ffffea00029d0980 refcount:1 mapcount:0 mapping:00000000ca5aa578 index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002472508 ffffea00027acc48 ffff8880aa000700
raw: 0000000000000000 ffff8880a7426000 0000000100000010 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a7425f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a7425f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a7426000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff8880a7426080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a7426100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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