Subject: KASAN: use-after-free Read in tls_sk_proto_close

From: syzbot <[email-masked]>
Date: Tue, 09 Jan 2018 08:09:01 -0800

Hello,

syzkaller hit the following crash on  
f4803f1b73f877a571be4c8e531dfcf190acc691
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.
Unfortunately, I don't have any reproducer for this bug yet.

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Reported-by: [email-masked]
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SELinux: unrecognized netlink message: protocol=0 nlmsg_type=24672  
sclass=netlink_route_socket pig=17852 comm=syz-executor1
==================================================================
BUG: KASAN: use-after-free in tls_sk_proto_close+0x7a0/0x800  
net/tls/tls_main.c:229
Read of size 8 at addr ffff8801d0352d88 by task syz-executor5/17854

CPU: 1 PID: 17854 Comm: syz-executor5 Not tainted 4.15.0-rc5+ #180
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x257 lib/dump_stack.c:53
  print_address_description+0x73/0x250 mm/kasan/report.c:252
  kasan_report_error mm/kasan/report.c:351 [inline]
  kasan_report+0x25b/0x340 mm/kasan/report.c:409
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
  tls_sk_proto_close+0x7a0/0x800 net/tls/tls_main.c:229
  inet_release+0xed/0x1c0 net/ipv4/af_inet.c:427
  sock_release+0x8d/0x1e0 net/socket.c:593
  sock_close+0x16/0x20 net/socket.c:1121
  __fput+0x327/0x7e0 fs/file_table.c:210
  ____fput+0x15/0x20 fs/file_table.c:244
  task_work_run+0x199/0x270 kernel/task_work.c:113
  exit_task_work include/linux/task_work.h:22 [inline]
  do_exit+0x9bb/0x1ad0 kernel/exit.c:865
  do_group_exit+0x149/0x400 kernel/exit.c:968
  get_signal+0x73f/0x16c0 kernel/signal.c:2335
  do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809
  exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158
  prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
  syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
  entry_SYSCALL_64_fastpath+0x98/0x9a
RIP: 0033:0x452ac9
RSP: 002b:00007f1de3b34ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000071c0f0 RCX: 0000000000452ac9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000071c0f0
RBP: 000000000071c0f0 R08: 00000000000003a3 R09: 000000000071c0c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000a2f7ef R14: 00007f1de3b359c0 R15: 0000000000000002

Allocated by task 17823:
  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:551
  kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3610
  kmalloc include/linux/slab.h:499 [inline]
  kzalloc include/linux/slab.h:688 [inline]
  tls_init+0x4b/0x240 net/tls/tls_main.c:458
  tcp_set_ulp+0x159/0x3e0 net/ipv4/tcp_ulp.c:127
  do_tcp_setsockopt.isra.37+0x316/0x2130 net/ipv4/tcp.c:2571
  tcp_setsockopt+0xb0/0xd0 net/ipv4/tcp.c:2874
  sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978
  SYSC_setsockopt net/socket.c:1821 [inline]
  SyS_setsockopt+0x189/0x360 net/socket.c:1800
  entry_SYSCALL_64_fastpath+0x23/0x9a

Freed by task 17854:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:447
  set_track mm/kasan/kasan.c:459 [inline]
  kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
  __cache_free mm/slab.c:3488 [inline]
  kfree+0xd6/0x260 mm/slab.c:3803
  tls_sk_proto_close+0x4bf/0x800 net/tls/tls_main.c:232
  inet_release+0xed/0x1c0 net/ipv4/af_inet.c:427
  sock_release+0x8d/0x1e0 net/socket.c:593
  sock_close+0x16/0x20 net/socket.c:1121
  __fput+0x327/0x7e0 fs/file_table.c:210
  ____fput+0x15/0x20 fs/file_table.c:244
  task_work_run+0x199/0x270 kernel/task_work.c:113
  exit_task_work include/linux/task_work.h:22 [inline]
  do_exit+0x9bb/0x1ad0 kernel/exit.c:865
  do_group_exit+0x149/0x400 kernel/exit.c:968
  get_signal+0x73f/0x16c0 kernel/signal.c:2335
  do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809
  exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158
  prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
  syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
  entry_SYSCALL_64_fastpath+0x98/0x9a

The buggy address belongs to the object at ffff8801d0352d00
  which belongs to the cache kmalloc-192 of size 192
The buggy address is located 136 bytes inside of
  192-byte region [ffff8801d0352d00, ffff8801d0352dc0)
The buggy address belongs to the page:
page:00000000b62f19e5 count:1 mapcount:0 mapping:0000000051db4587 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d0352000 0000000000000000 0000000100000010
raw: ffffea000743c820 ffffea0006fb82e0 ffff8801dac00040 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8801d0352c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
  ffff8801d0352d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8801d0352d80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                       ^
  ffff8801d0352e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801d0352e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

---
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