PPPIOCDETACH file->f_count=2
audit: type=1400 audit(1521835857.794:89): avc:  denied  { map } for  pid=9629 comm="syz-executor0" path="/sys/kernel/debug/kcov" dev="debugfs" ino=1048 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:debugfs_t:s0 tclass=file permissive=1
PPPIOCDETACH file->f_count=2
IPVS: ftp: loaded support on port[0] = 21
==================================================================
BUG: KASAN: use-after-free in inet_create+0xd9c/0xf50 net/ipv4/af_inet.c:339
Read of size 4 at addr ffff8801d28ba504 by task kworker/u4:3/86
audit: type=1400 audit(1521835858.532:90): avc:  denied  { map } for  pid=9670 comm="sh" path="/bin/dash" dev="sda1" ino=1473 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1

CPU: 0 PID: 86 Comm: kworker/u4:3 Not tainted 4.16.0-rc6+ #273
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: krdsd rds_connect_worker
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x24d lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report+0x23c/0x360 mm/kasan/report.c:412
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 inet_create+0xd9c/0xf50 net/ipv4/af_inet.c:339
 __sock_create+0x4d4/0x850 net/socket.c:1285
 sock_create_kern+0x3f/0x50 net/socket.c:1331
 rds_tcp_conn_path_connect+0x277/0x940 net/rds/tcp_connect.c:108
 rds_connect_worker+0x156/0x1f0 net/rds/threads.c:175
 process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113
 worker_thread+0x223/0x1990 kernel/workqueue.c:2247
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406

Allocated by task 4290:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3541
 kmem_cache_zalloc include/linux/slab.h:691 [inline]
 net_alloc net/core/net_namespace.c:369 [inline]
 copy_net_ns+0x152/0x580 net/core/net_namespace.c:409
 create_new_namespaces+0x425/0x880 kernel/nsproxy.c:107
 unshare_nsproxy_namespaces+0xae/0x1e0 kernel/nsproxy.c:206
 SYSC_unshare kernel/fork.c:2407 [inline]
 SyS_unshare+0x653/0xfa0 kernel/fork.c:2357
 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline]
 do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 86:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527
 __cache_free mm/slab.c:3485 [inline]
 kmem_cache_free+0x83/0x2a0 mm/slab.c:3743
 net_free+0xca/0x110 net/core/net_namespace.c:385
 net_drop_ns.part.11+0x26/0x30 net/core/net_namespace.c:392
 net_drop_ns net/core/net_namespace.c:391 [inline]
 cleanup_net+0x977/0xcb0 net/core/net_namespace.c:535
 process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113
 worker_thread+0x223/0x1990 kernel/workqueue.c:2247
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406

The buggy address belongs to the object at ffff8801d28ba040
 which belongs to the cache net_namespace of size 6720
The buggy address is located 1220 bytes inside of
 6720-byte region [ffff8801d28ba040, ffff8801d28bba80)
The buggy address belongs to the page:
page:ffffea00074a2e80 count:1 mapcount:0 mapping:ffff8801d28ba040 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801d28ba040 0000000000000000 0000000100000001
raw: ffff8801d9bce548 ffffea0006e811a0 ffff8801d9bece00 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d28ba400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d28ba480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801d28ba500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8801d28ba580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d28ba600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================