RDX: 00000000fffffdef RSI: 00000000200005c0 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000020000000 R09: 000000000000001c
R10: 0000000000000040 R11: 0000000000000246 R12: 0000000000000015
R13: 00000000000005d8 R14: 00000000006fdce0 R15: 0000000000000002
==================================================================
BUG: KASAN: use-after-free in tls_fill_prepend include/net/tls.h:339 [inline]
BUG: KASAN: use-after-free in tls_push_record+0x1023/0x13e0 net/tls/tls_sw.c:240
Write of size 1 at addr ffff8801c0850000 by task syz-executor6/20292

CPU: 1 PID: 20292 Comm: syz-executor6 Not tainted 4.17.0-rc6+ #74
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_store1_noabort+0x17/0x20 mm/kasan/report.c:435
 tls_fill_prepend include/net/tls.h:339 [inline]
 tls_push_record+0x1023/0x13e0 net/tls/tls_sw.c:240
 tls_sw_push_pending_record+0x22/0x30 net/tls/tls_sw.c:276
 tls_push_pending_closed_record+0x10c/0x150 net/tls/tls_main.c:211
 tls_complete_pending_work include/net/tls.h:277 [inline]
 tls_sk_proto_close+0x893/0xa70 net/tls/tls_main.c:263
 inet_release+0x104/0x1f0 net/ipv4/af_inet.c:427
 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:459
 sock_release+0x96/0x1b0 net/socket.c:594
 sock_close+0x16/0x20 net/socket.c:1149
 __fput+0x34d/0x890 fs/file_table.c:209
 ____fput+0x15/0x20 fs/file_table.c:243
 task_work_run+0x1e4/0x290 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xf89/0x2730 kernel/exit.c:865
 do_group_exit+0x16f/0x430 kernel/exit.c:968
 __do_sys_exit_group kernel/exit.c:979 [inline]
 __se_sys_exit_group kernel/exit.c:977 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:977
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455a09
RSP: 002b:0000000000a3ea98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000164 RCX: 0000000000455a09
RDX: 00000000000005d8 RSI: 0000000000730c20 RDI: 0000000000000000
RBP: 0000000000000013 R08: 0000000000000663 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000013
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000001380

The buggy address belongs to the page:
page:ffffea0007021400 count:1 mapcount:-511 mapping:0000000000000000 index:0x0
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 0000000000000000 0000000000000000 00000001fffffe00
raw: dead000000000100 dead000000000200 0000000000000000 ffff8801c4d7e140
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8801c4d7e140

Memory state around the buggy address:
 ffff8801c084ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801c084ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801c0850000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                   ^
 ffff8801c0850080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801c0850100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================