audit_printk_skb: 30 callbacks suppressed
audit: type=1400 audit(2000000132.226:3053): avc:  denied  { create } for  pid=27784 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=27778 comm=syz-executor.5
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=27778 comm=syz-executor.5
==================================================================
BUG: KASAN: use-after-free in tcp_connect+0x26c2/0x30b0 net/ipv4/tcp_output.c:3417
Read of size 4 at addr ffff8801a83bc528 by task syz-executor.3/27788

CPU: 1 PID: 27788 Comm: syz-executor.3 Not tainted 4.9.180+ #4
 ffff88019cc97940 ffffffff81b577f1 0000000000000000 ffffea0006a0ef00
 ffff8801a83bc528 0000000000000004 ffffffff82527c52 ffff88019cc97978
 ffffffff8150a828 0000000000000000 ffff8801a83bc528 ffff8801a83bc528
Call Trace:
 [<00000000aa043c07>] __dump_stack lib/dump_stack.c:15 [inline]
 [<00000000aa043c07>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<0000000011fd3e82>] print_address_description+0x6f/0x23a mm/kasan/report.c:256
 [<0000000003fd12fe>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<0000000003fd12fe>] kasan_report mm/kasan/report.c:413 [inline]
 [<0000000003fd12fe>] kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:397
 [<00000000933832df>] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:433
 [<00000000e2bc61ad>] tcp_connect+0x26c2/0x30b0 net/ipv4/tcp_output.c:3417
 [<000000004ea58064>] tcp_v6_connect+0x13df/0x1ad0 net/ipv6/tcp_ipv6.c:298
 [<00000000c567d810>] __inet_stream_connect+0x706/0xbf0 net/ipv4/af_inet.c:623
 [<00000000c766c239>] inet_stream_connect+0x55/0xa0 net/ipv4/af_inet.c:687
 [<0000000000d6f483>] SYSC_connect net/socket.c:1576 [inline]
 [<0000000000d6f483>] SyS_connect+0x1a5/0x2e0 net/socket.c:1557
 [<000000006e3e4d8b>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
 [<000000008ac4745d>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Allocated by task 27797:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack mm/kasan/kasan.c:512 [inline]
 set_track mm/kasan/kasan.c:524 [inline]
 kasan_kmalloc.part.0+0x62/0xf0 mm/kasan/kasan.c:616
 kasan_kmalloc+0xb7/0xd0 mm/kasan/kasan.c:601
 kasan_slab_alloc+0xf/0x20 mm/kasan/kasan.c:554
 slab_post_alloc_hook mm/slab.h:417 [inline]
 slab_alloc_node mm/slub.c:2715 [inline]
 slab_alloc mm/slub.c:2723 [inline]
 kmem_cache_alloc+0xd5/0x2b0 mm/slub.c:2728
 kmem_cache_alloc_node include/linux/slab.h:364 [inline]
 __alloc_skb+0xe7/0x5e0 net/core/skbuff.c:219
 alloc_skb_fclone include/linux/skbuff.h:966 [inline]
 sk_stream_alloc_skb+0xa3/0x5d0 net/ipv4/tcp.c:828
 tcp_sendmsg+0xe8d/0x2f90 net/ipv4/tcp.c:1230
 inet_sendmsg+0x202/0x4d0 net/ipv4/af_inet.c:766
 sock_sendmsg_nosec net/socket.c:649 [inline]
 sock_sendmsg+0xbe/0x110 net/socket.c:659
 ___sys_sendmsg+0x78b/0x8b0 net/socket.c:1983
 __sys_sendmsg+0xc8/0x170 net/socket.c:2017
 SYSC_sendmsg net/socket.c:2028 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2024
 do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
 entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Freed by task 27788:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack mm/kasan/kasan.c:512 [inline]
 set_track mm/kasan/kasan.c:524 [inline]
 kasan_slab_free+0xb0/0x190 mm/kasan/kasan.c:589
 slab_free_hook mm/slub.c:1355 [inline]
 slab_free_freelist_hook mm/slub.c:1377 [inline]
 slab_free mm/slub.c:2958 [inline]
 kmem_cache_free+0xbe/0x310 mm/slub.c:2980
 kfree_skbmem+0x82/0x100 net/core/skbuff.c:648
 __kfree_skb+0x1e/0x30 net/core/skbuff.c:689
 sk_wmem_free_skb include/net/sock.h:1368 [inline]
 tcp_write_queue_purge include/net/tcp.h:1530 [inline]
 tcp_connect_init net/ipv4/tcp_output.c:3257 [inline]
 tcp_connect+0xa9b/0x30b0 net/ipv4/tcp_output.c:3388
 tcp_v6_connect+0x13df/0x1ad0 net/ipv6/tcp_ipv6.c:298
 __inet_stream_connect+0x706/0xbf0 net/ipv4/af_inet.c:623
 inet_stream_connect+0x55/0xa0 net/ipv4/af_inet.c:687
 SYSC_connect net/socket.c:1576 [inline]
 SyS_connect+0x1a5/0x2e0 net/socket.c:1557
 do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
 entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the object at ffff8801a83bc500
 which belongs to the cache skbuff_fclone_cache of size 456
The buggy address is located 40 bytes inside of
 456-byte region [ffff8801a83bc500, ffff8801a83bc6c8)
The buggy address belongs to the page:
page:ffffea0006a0ef00 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
flags: 0x4000000000010200(slab|head)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801a83bc400: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff8801a83bc480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801a83bc500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff8801a83bc580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801a83bc600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================