KASAN: global-out-of-bounds Read in __aa_lookupn_ns

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 02214bfc89c7 Merge tag 'media/v4.19-2' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1456f8a1400000
kernel config: https://syzkaller.appspot.com/x/.config?x=22a62640793a83c9
dashboard link: https://syzkaller.appspot.com/bug?extid=71b6643475f707f93fdc
compiler: gcc (GCC) 8.0.1 20180413 (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+71b664...@syzkaller.appspotmail.com

sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3038
__sys_setsockopt+0x1ba/0x3c0 net/socket.c:1902
__do_sys_setsockopt net/socket.c:1913 [inline]
__se_sys_setsockopt net/socket.c:1910 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
==================================================================
BUG: KASAN: global-out-of-bounds in memcmp+0xe3/0x160 lib/string.c:861
Read of size 1 at addr ffffffff88000008 by task syz-executor0/10914

entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457579
Code: 1d b4 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 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4c14533c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f4c14533c90 RCX: 0000000000457579
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 000000000072bf00 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000020000080 R11: 0000000000000246 R12: 00007f4c145346d4
R13: 00000000004c3ed9 R14: 00000000004d6260 R15: 0000000000000004
CPU: 0 PID: 10914 Comm: syz-executor0 Not tainted 4.19.0-rc5+ #252
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+0x1c4/0x2b4 lib/dump_stack.c:113
print_address_description.cold.8+0x58/0x1ff mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
__asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
memcmp+0xe3/0x160 lib/string.c:861
strnstr+0x4b/0x70 lib/string.c:934
__aa_lookupn_ns+0xc1/0x570 security/apparmor/policy_ns.c:209
aa_lookupn_ns+0x88/0x1e0 security/apparmor/policy_ns.c:240
aa_fqlookupn_profile+0x1b9/0x1010 security/apparmor/policy.c:468
fqlookupn_profile+0x80/0xc0 security/apparmor/label.c:1844
aa_label_strn_parse+0xa3a/0x1230 security/apparmor/label.c:1908
aa_label_parse+0x42/0x50 security/apparmor/label.c:1943
aa_change_profile+0x513/0x3510 security/apparmor/domain.c:1362
apparmor_setprocattr+0xa8b/0x1150 security/apparmor/lsm.c:656
security_setprocattr+0x66/0xc0 security/security.c:1298
proc_pid_attr_write+0x301/0x540 fs/proc/base.c:2555
__vfs_write+0x119/0x9f0 fs/read_write.c:485
vfs_write+0x1fc/0x560 fs/read_write.c:549
ksys_write+0x101/0x260 fs/read_write.c:598
__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457579
Code: 1d b4 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 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5a92ec2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579
RDX: 000000000000002c RSI: 00000000200000c0 RDI: 0000000000000004
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5a92ec36d4
R13: 00000000004c5454 R14: 00000000004d8c78 R15: 00000000ffffffff

CPU: 1 PID: 10921 Comm: syz-executor3 Not tainted 4.19.0-rc5+ #252
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
The buggy address belongs to the variable:
__start_rodata+0x8/0x1000
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113

Memory state around the buggy address:
ffffffff87ffff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffffff87ffff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
fail_dump lib/fault-inject.c:51 [inline]
should_fail.cold.4+0xa/0x17 lib/fault-inject.c:149
> ffffffff88000000: 00 fa fa fa fa fa fa fa 00 01 fa fa fa fa fa fa
^
ffffffff88000080: 00 00 00 07 fa fa fa fa 00 04 fa fa fa fa fa fa
ffffffff88000100: 05 fa fa fa fa fa fa fa 00 00 00 00 05 fa fa fa
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.

[Dmitry Vyukov]

On Wed, Sep 26, 2018 at 9:54 AM, syzbot
<syzbot+71b664...@syzkaller.appspotmail.com> wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 02214bfc89c7 Merge tag 'media/v4.19-2' of git://git.kernel..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1456f8a1400000
> kernel config: https://syzkaller.appspot.com/x/.config?x=22a62640793a83c9
> dashboard link: https://syzkaller.appspot.com/bug?extid=71b6643475f707f93fdc
> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.

Again misattributed to net. This misattribution should now be fixed by:
https://github.com/google/syzkaller/commit/db716d6653d073b0abfb51186cd4ac2d5418c9c6
Adding security/apparmor/policy_ns.c maintainers explicitly.

> --
> You received this message because you are subscribed to the Google Groups
> "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to syzkaller-bug...@googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/syzkaller-bugs/000000000000a7487d0576c18693%40google.com.
> For more options, visit https://groups.google.com/d/optout.

[Dmitry Vyukov]

On Wed, Sep 26, 2018 at 12:06 PM, Dmitry Vyukov <dvy...@google.com> wrote:
> On Wed, Sep 26, 2018 at 9:54 AM, syzbot
> <syzbot+71b664...@syzkaller.appspotmail.com> wrote:
>> Hello,
>>
>> syzbot found the following crash on:
>>
>> HEAD commit: 02214bfc89c7 Merge tag 'media/v4.19-2' of git://git.kernel..
>> git tree: upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=1456f8a1400000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=22a62640793a83c9
>> dashboard link: https://syzkaller.appspot.com/bug?extid=71b6643475f707f93fdc
>> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>>
>> Unfortunately, I don't have any reproducer for this crash yet.
>
> Again misattributed to net. This misattribution should now be fixed by:
> https://github.com/google/syzkaller/commit/db716d6653d073b0abfb51186cd4ac2d5418c9c6
> Adding security/apparmor/policy_ns.c maintainers explicitly.

This is the same as "KASAN: stack-out-of-bounds Read in __aa_lookupn_ns":
https://syzkaller.appspot.com/bug?id=f0d603856d8b3cc9b8e09228f2f548c18ef907ac
right?

[John Johansen]

On 09/28/2018 01:39 AM, Dmitry Vyukov wrote:
> On Wed, Sep 26, 2018 at 12:06 PM, Dmitry Vyukov <dvy...@google.com> wrote:
>> On Wed, Sep 26, 2018 at 9:54 AM, syzbot
>> <syzbot+71b664...@syzkaller.appspotmail.com> wrote:
>>> Hello,
>>>
>>> syzbot found the following crash on:
>>>
>>> HEAD commit: 02214bfc89c7 Merge tag 'media/v4.19-2' of git://git.kernel..
>>> git tree: upstream
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1456f8a1400000
>>> kernel config: https://syzkaller.appspot.com/x/.config?x=22a62640793a83c9
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=71b6643475f707f93fdc
>>> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>>>
>>> Unfortunately, I don't have any reproducer for this crash yet.
>>
>> Again misattributed to net. This misattribution should now be fixed by:
>> https://github.com/google/syzkaller/commit/db716d6653d073b0abfb51186cd4ac2d5418c9c6
>> Adding security/apparmor/policy_ns.c maintainers explicitly.
>
> This is the same as "KASAN: stack-out-of-bounds Read in __aa_lookupn_ns":
> https://syzkaller.appspot.com/bug?id=f0d603856d8b3cc9b8e09228f2f548c18ef907ac
> right?
>

yes it looks like it is

[Dmitry Vyukov]

On Fri, Sep 28, 2018 at 3:19 PM, John Johansen
<john.j...@canonical.com> wrote:
> On 09/28/2018 01:39 AM, Dmitry Vyukov wrote:
>> On Wed, Sep 26, 2018 at 12:06 PM, Dmitry Vyukov <dvy...@google.com> wrote:
>>> On Wed, Sep 26, 2018 at 9:54 AM, syzbot
>>> <syzbot+71b664...@syzkaller.appspotmail.com> wrote:
>>>> Hello,
>>>>
>>>> syzbot found the following crash on:
>>>>
>>>> HEAD commit: 02214bfc89c7 Merge tag 'media/v4.19-2' of git://git.kernel..
>>>> git tree: upstream
>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1456f8a1400000
>>>> kernel config: https://syzkaller.appspot.com/x/.config?x=22a62640793a83c9
>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=71b6643475f707f93fdc
>>>> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>>>>
>>>> Unfortunately, I don't have any reproducer for this crash yet.
>>>
>>> Again misattributed to net. This misattribution should now be fixed by:
>>> https://github.com/google/syzkaller/commit/db716d6653d073b0abfb51186cd4ac2d5418c9c6
>>> Adding security/apparmor/policy_ns.c maintainers explicitly.
>>
>> This is the same as "KASAN: stack-out-of-bounds Read in __aa_lookupn_ns":
>> https://syzkaller.appspot.com/bug?id=f0d603856d8b3cc9b8e09228f2f548c18ef907ac
>> right?
>>
>
> yes it looks like it is

Let's tell syzbot then, otherwise it will consider it as open forever:

#syz dup: KASAN: stack-out-of-bounds Read in __aa_lookupn_ns

> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bug...@googlegroups.com.

> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/23948464-72d2-7d04-59b5-79606c24ed75%40canonical.com.