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BUG: KASAN: use-after-free in inet_ctl_sock_destroy include/net/inet_common.h:56 [inline]
BUG: KASAN: use-after-free in tcp_sk_exit+0x20d/0x240 net/ipv4/tcp_ipv4.c:2585
Read of size 8 at addr ffff8880606d9720 by task kworker/u4:8/8269

CPU: 1 PID: 8269 Comm: kworker/u4:8 Not tainted 5.1.0-rc5+ #176
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 inet_ctl_sock_destroy include/net/inet_common.h:56 [inline]
 tcp_sk_exit+0x20d/0x240 net/ipv4/tcp_ipv4.c:2585
 ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:153
 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:552
 process_one_work+0x98e/0x1790 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x357/0x430 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Allocated by task 28451:
 save_stack+0x45/0xd0 mm/kasan/common.c:75
 set_track mm/kasan/common.c:87 [inline]
 __kasan_kmalloc mm/kasan/common.c:497 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:505
 slab_post_alloc_hook mm/slab.h:437 [inline]
 slab_alloc mm/slab.c:3394 [inline]
 kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3556
 sk_prot_alloc+0x67/0x2e0 net/core/sock.c:1601
 sk_alloc+0x39/0xf70 net/core/sock.c:1661
 inet_create net/ipv4/af_inet.c:321 [inline]
 inet_create+0x36a/0xe10 net/ipv4/af_inet.c:247
 __sock_create+0x3e6/0x750 net/socket.c:1398
 sock_create_kern+0x3b/0x50 net/socket.c:1467
 inet_ctl_sock_create+0x9d/0x1f0 net/ipv4/af_inet.c:1623
 tcp_sk_init+0x11b/0x12d0 net/ipv4/tcp_ipv4.c:2600
 ops_init+0xb6/0x410 net/core/net_namespace.c:129
 setup_net+0x2d3/0x740 net/core/net_namespace.c:315
 copy_net_ns+0x1df/0x340 net/core/net_namespace.c:438
 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107
 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206
 ksys_unshare+0x440/0x980 kernel/fork.c:2549
 __do_sys_unshare kernel/fork.c:2617 [inline]
 __se_sys_unshare kernel/fork.c:2615 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:2615
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 3032:
 save_stack+0x45/0xd0 mm/kasan/common.c:75
 set_track mm/kasan/common.c:87 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467
 __cache_free mm/slab.c:3500 [inline]
 kmem_cache_free+0x86/0x260 mm/slab.c:3766
 sk_prot_free net/core/sock.c:1642 [inline]
 __sk_destruct+0x4b6/0x6d0 net/core/sock.c:1726
 sk_destruct+0x7b/0x90 net/core/sock.c:1734
 __sk_free+0xce/0x300 net/core/sock.c:1745
 sk_free+0x42/0x50 net/core/sock.c:1756
 sock_put include/net/sock.h:1714 [inline]
 sk_common_release+0x224/0x330 net/core/sock.c:3171
 raw_close+0x22/0x30 net/ipv4/raw.c:708
 inet_release+0x105/0x1f0 net/ipv4/af_inet.c:428
 __sock_release+0x1fe/0x2b0 net/socket.c:599
 sock_release+0x18/0x20 net/socket.c:619
 inet_ctl_sock_destroy include/net/inet_common.h:56 [inline]
 tcp_sk_exit+0x185/0x240 net/ipv4/tcp_ipv4.c:2585
 ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:153
 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:552
 process_one_work+0x98e/0x1790 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x357/0x430 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8880606d9700
 which belongs to the cache RAW(66:syz4) of size 1328
The buggy address is located 32 bytes inside of
 1328-byte region [ffff8880606d9700, ffff8880606d9c30)
The buggy address belongs to the page:
page:ffffea000181b600 count:1 mapcount:0 mapping:ffff888096aaf640 index:0xffff8880606d8b80 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffff8880a60e5b38 ffffea00023f5e88 ffff888096aaf640
raw: ffff8880606d8b80 ffff8880606d8000 0000000100000004 ffff888069904680
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff888069904680

Memory state around the buggy address:
 ffff8880606d9600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
 ffff8880606d9680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880606d9700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff8880606d9780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880606d9800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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