KASAN: invalid-free in tls_sk_proto_cleanup

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: fde50b96 Add linux-next specific files for 20190726
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15ea7f3fa00000
kernel config: https://syzkaller.appspot.com/x/.config?x=4b58274564b354c1
dashboard link: https://syzkaller.appspot.com/bug?extid=f5731e2256eb5130dbd6
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+f5731e...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: double-free or invalid-free in tls_sk_proto_cleanup+0x216/0x3e0
net/tls/tls_main.c:300

CPU: 0 PID: 19107 Comm: syz-executor.4 Not tainted 5.3.0-rc1-next-20190726
#53
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+0x172/0x1f0 lib/dump_stack.c:113
print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351
kasan_report_invalid_free+0x65/0xa0 mm/kasan/report.c:444
__kasan_slab_free+0x13a/0x150 mm/kasan/common.c:427
kasan_slab_free+0xe/0x10 mm/kasan/common.c:456
__cache_free mm/slab.c:3425 [inline]
kfree+0x10a/0x2c0 mm/slab.c:3756
tls_sk_proto_cleanup+0x216/0x3e0 net/tls/tls_main.c:300
tls_sk_proto_unhash+0x90/0x3f0 net/tls/tls_main.c:330
tcp_set_state+0x5b9/0x7d0 net/ipv4/tcp.c:2235
tcp_done+0xe2/0x320 net/ipv4/tcp.c:3824
tcp_reset+0x132/0x500 net/ipv4/tcp_input.c:4080
tcp_validate_incoming+0xa2d/0x1660 net/ipv4/tcp_input.c:5440
tcp_rcv_established+0x6b5/0x1e70 net/ipv4/tcp_input.c:5648
tcp_v6_do_rcv+0x41e/0x12c0 net/ipv6/tcp_ipv6.c:1356
sk_backlog_rcv include/net/sock.h:945 [inline]
__release_sock+0x129/0x390 net/core/sock.c:2418
release_sock+0x59/0x1c0 net/core/sock.c:2934
sk_stream_wait_memory+0x65a/0xfc0 net/core/stream.c:149
tls_sw_sendmsg+0x673/0x17b0 net/tls/tls_sw.c:1054
inet6_sendmsg+0x9e/0xe0 net/ipv6/af_inet6.c:576
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:657
__sys_sendto+0x262/0x380 net/socket.c:1952
__do_sys_sendto net/socket.c:1964 [inline]
__se_sys_sendto net/socket.c:1960 [inline]
__x64_sys_sendto+0xe1/0x1a0 net/socket.c:1960
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459829
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fcee5e02c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000459829
RDX: ffffffffffffffc1 RSI: 00000000200005c0 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 1201000000003618
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcee5e036d4
R13: 00000000004c77c1 R14: 00000000004dcf38 R15: 00000000ffffffff

Allocated by task 19107:
save_stack+0x23/0x90 mm/kasan/common.c:69
set_track mm/kasan/common.c:77 [inline]
__kasan_kmalloc mm/kasan/common.c:486 [inline]
__kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:459
kasan_kmalloc+0x9/0x10 mm/kasan/common.c:500
__do_kmalloc mm/slab.c:3655 [inline]
__kmalloc_track_caller+0x15f/0x760 mm/slab.c:3670
kmemdup+0x27/0x60 mm/util.c:120
kmemdup include/linux/string.h:477 [inline]
tls_set_sw_offload+0xb3a/0x1567 net/tls/tls_sw.c:2361
do_tls_setsockopt_conf net/tls/tls_main.c:581 [inline]
do_tls_setsockopt net/tls/tls_main.c:630 [inline]
tls_setsockopt+0x4d5/0x8d0 net/tls/tls_main.c:649
sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3130
__sys_setsockopt+0x261/0x4c0 net/socket.c:2084
__do_sys_setsockopt net/socket.c:2100 [inline]
__se_sys_setsockopt net/socket.c:2097 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:2097
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 19107:
save_stack+0x23/0x90 mm/kasan/common.c:69
set_track mm/kasan/common.c:77 [inline]
__kasan_slab_free+0x102/0x150 mm/kasan/common.c:448
kasan_slab_free+0xe/0x10 mm/kasan/common.c:456
__cache_free mm/slab.c:3425 [inline]
kfree+0x10a/0x2c0 mm/slab.c:3756
tls_sk_proto_cleanup+0x216/0x3e0 net/tls/tls_main.c:300
tls_sk_proto_unhash+0x90/0x3f0 net/tls/tls_main.c:330
tcp_set_state+0x5b9/0x7d0 net/ipv4/tcp.c:2235
tcp_done+0xe2/0x320 net/ipv4/tcp.c:3824
tcp_reset+0x132/0x500 net/ipv4/tcp_input.c:4080
tcp_validate_incoming+0xa2d/0x1660 net/ipv4/tcp_input.c:5440
tcp_rcv_established+0x6b5/0x1e70 net/ipv4/tcp_input.c:5648
tcp_v6_do_rcv+0x41e/0x12c0 net/ipv6/tcp_ipv6.c:1356
sk_backlog_rcv include/net/sock.h:945 [inline]
__release_sock+0x129/0x390 net/core/sock.c:2418
release_sock+0x59/0x1c0 net/core/sock.c:2934
wait_on_pending_writer+0x20f/0x420 net/tls/tls_main.c:91
tls_sk_proto_cleanup+0x2c5/0x3e0 net/tls/tls_main.c:295
tls_sk_proto_unhash+0x90/0x3f0 net/tls/tls_main.c:330
tcp_set_state+0x5b9/0x7d0 net/ipv4/tcp.c:2235
tcp_done+0xe2/0x320 net/ipv4/tcp.c:3824
tcp_reset+0x132/0x500 net/ipv4/tcp_input.c:4080
tcp_validate_incoming+0xa2d/0x1660 net/ipv4/tcp_input.c:5440
tcp_rcv_established+0x6b5/0x1e70 net/ipv4/tcp_input.c:5648
tcp_v6_do_rcv+0x41e/0x12c0 net/ipv6/tcp_ipv6.c:1356
sk_backlog_rcv include/net/sock.h:945 [inline]
__release_sock+0x129/0x390 net/core/sock.c:2418
release_sock+0x59/0x1c0 net/core/sock.c:2934
sk_stream_wait_memory+0x65a/0xfc0 net/core/stream.c:149
tls_sw_sendmsg+0x673/0x17b0 net/tls/tls_sw.c:1054
inet6_sendmsg+0x9e/0xe0 net/ipv6/af_inet6.c:576
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:657
__sys_sendto+0x262/0x380 net/socket.c:1952
__do_sys_sendto net/socket.c:1964 [inline]
__se_sys_sendto net/socket.c:1960 [inline]
__x64_sys_sendto+0xe1/0x1a0 net/socket.c:1960
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88808ff1c500
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
32-byte region [ffff88808ff1c500, ffff88808ff1c520)
The buggy address belongs to the page:
page:ffffea00023fc700 refcount:1 mapcount:0 mapping:ffff8880aa4001c0
index:0xffff88808ff1cfc1
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea0002a12308 ffffea0002912208 ffff8880aa4001c0
raw: ffff88808ff1cfc1 ffff88808ff1c000 0000000100000024 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88808ff1c400: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
ffff88808ff1c480: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
> ffff88808ff1c500: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
^
ffff88808ff1c580: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
ffff88808ff1c600: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================


---
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[Jakub Kicinski]

On Wed, 31 Jul 2019 01:29:05 -0700, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: fde50b96 Add linux-next specific files for 20190726
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=15ea7f3fa00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=4b58274564b354c1
> dashboard link: https://syzkaller.appspot.com/bug?extid=f5731e2256eb5130dbd6
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+f5731e...@syzkaller.appspotmail.com
>
> ==================================================================
> BUG: KASAN: double-free or invalid-free in tls_sk_proto_cleanup+0x216/0x3e0
> net/tls/tls_main.c:300

FWIW there is a fix in the works for this and all new TLS issues.
I think John and Eric didn't have time yet to look at my theories,
so I'd like to keep it in QA for one extra day before posting.

[Jakub Kicinski]

#syz fix: net/tls: partially revert fix transition through disconnect with close