audit: type=1400 audit(1584575395.900:4989): avc:  denied  { map } for  pid=22618 comm="syz-executor.3" path="/root/syz-executor.3" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=0
==================================================================
BUG: KASAN: use-after-free in route4_destroy+0x698/0x7e0 net/sched/cls_route.c:298
Read of size 8 at addr ffff8880915cfa00 by task kworker/u4:2/83

CPU: 1 PID: 83 Comm: kworker/u4:2 Not tainted 4.19.111-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 print_address_description.cold+0x7c/0x212 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+0x88/0x2b9 mm/kasan/report.c:396
 route4_destroy+0x698/0x7e0 net/sched/cls_route.c:298
 tcf_proto_destroy+0x5d/0xe0 net/sched/cls_api.c:190
 tcf_chain_flush+0x1ed/0x330 net/sched/cls_api.c:362
 tcf_block_put_ext.part.0+0x418/0x9a0 net/sched/cls_api.c:770
 tcf_block_put_ext net/sched/cls_api.c:754 [inline]
 tcf_block_put+0xad/0xf8 net/sched/cls_api.c:797
 hfsc_destroy_qdisc+0xe0/0x280 net/sched/sch_hfsc.c:1509
 qdisc_destroy+0x17c/0x6b0 net/sched/sch_generic.c:982
 dev_shutdown+0x2b5/0x47a net/sched/sch_generic.c:1300
 rollback_registered_many+0x64a/0xc40 net/core/dev.c:8173
 unregister_netdevice_many.part.0+0x16/0x1e0 net/core/dev.c:9294
 unregister_netdevice_many net/core/dev.c:9293 [inline]
 default_device_exit_batch+0x2ff/0x3c0 net/core/dev.c:9765
 ops_exit_list.isra.0+0xef/0x140 net/core/net_namespace.c:156
 cleanup_net+0x3bf/0x850 net/core/net_namespace.c:553
 process_one_work+0x91f/0x1640 kernel/workqueue.c:2155
 worker_thread+0x96/0xe20 kernel/workqueue.c:2298
 kthread+0x34a/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 20764:
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531
 kmem_cache_alloc_trace+0x14d/0x7a0 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 route4_change+0x2a5/0x2210 net/sched/cls_route.c:495
 tc_new_tfilter+0xa6b/0x1450 net/sched/cls_api.c:1320
 rtnetlink_rcv_msg+0x453/0xaf0 net/core/rtnetlink.c:4777
 netlink_rcv_skb+0x160/0x410 net/netlink/af_netlink.c:2455
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x4d7/0x6a0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x80b/0xcd0 net/netlink/af_netlink.c:1909
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:632
 ___sys_sendmsg+0x803/0x920 net/socket.c:2115
 __sys_sendmsg+0xec/0x1b0 net/socket.c:2153
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8231:
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xce/0x220 mm/slab.c:3822
 route4_delete_filter_work+0x17/0x20 net/sched/cls_route.c:270
 process_one_work+0x91f/0x1640 kernel/workqueue.c:2155
 worker_thread+0x96/0xe20 kernel/workqueue.c:2298
 kthread+0x34a/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

The buggy address belongs to the object at ffff8880915cfa00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 0 bytes inside of
 192-byte region [ffff8880915cfa00, ffff8880915cfac0)
The buggy address belongs to the page:
page:ffffea00024573c0 count:1 mapcount:0 mapping:ffff88812c3dc040 index:0xffff8880915cfd00
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea000224f648 ffffea0002998248 ffff88812c3dc040
raw: ffff8880915cfd00 ffff8880915cf000 000000010000000a 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880915cf900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880915cf980: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
>ffff8880915cfa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8880915cfa80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880915cfb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================