syzbot

gfs2: invalid mount option: v
gfs2: can't parse mount arguments
bond0 (unregistering): Released all slaves
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BUG: KASAN: use-after-free in inet_create+0xf3d/0x10a0 net/ipv4/af_inet.c:339
Read of size 4 at addr ffff88018f6547c4 by task kworker/u4:5/6401

CPU: 1 PID: 6401 Comm: kworker/u4:5 Not tainted 4.16.0+ #14
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:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0xac/0x2f5 mm/kasan/report.c:412
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 inet_create+0xf3d/0x10a0 net/ipv4/af_inet.c:339
 __sock_create+0x526/0x920 net/socket.c:1285
 sock_create_kern+0x3b/0x50 net/socket.c:1331
 rds_tcp_conn_path_connect+0x2a3/0x960 net/rds/tcp_connect.c:108
 rds_connect_worker+0x190/0x260 net/rds/threads.c:175
 process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145
 worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411

Allocated by task 4491:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
 kmem_cache_zalloc include/linux/slab.h:691 [inline]
 net_alloc net/core/net_namespace.c:383 [inline]
 copy_net_ns+0x159/0x4c0 net/core/net_namespace.c:423
 create_new_namespaces+0x69d/0x8f0 kernel/nsproxy.c:107
 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206
 ksys_unshare+0x708/0xfb0 kernel/fork.c:2409
 SYSC_unshare kernel/fork.c:2477 [inline]
 SyS_unshare+0x15/0x20 kernel/fork.c:2475
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 6401:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
 net_free net/core/net_namespace.c:399 [inline]
 net_drop_ns.part.14+0x11a/0x130 net/core/net_namespace.c:406
 net_drop_ns net/core/net_namespace.c:405 [inline]
 cleanup_net+0x6a1/0xb20 net/core/net_namespace.c:541
 process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145
 worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411

The buggy address belongs to the object at ffff88018f6540c0
 which belongs to the cache net_namespace of size 8768
The buggy address is located 1796 bytes inside of
 8768-byte region [ffff88018f6540c0, ffff88018f656300)
The buggy address belongs to the page:
page:ffffea00063d9500 count:1 mapcount:0 mapping:ffff88018f6540c0 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff88018f6540c0 0000000000000000 0000000100000001
raw: ffffea00063d9320 ffffea0006388c20 ffff8801d9fd5e40 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88018f654680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88018f654700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88018f654780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88018f654800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88018f654880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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