LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
* Re: Re: [Fix kernel crash in cipso_v4_sock_delattr ]
@ 2015-03-31  5:09 Maninder Singh
  2015-03-31 17:52 ` Casey Schaufler
  0 siblings, 1 reply; 3+ messages in thread
From: Maninder Singh @ 2015-03-31  5:09 UTC (permalink / raw)
  To: Casey Schaufler, Paul Moore, Maninder Singh
  Cc: davem, netdev, linux-kernel, Vaneet Narang, AJEET YADAV

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=windows-1252, Size: 2027 bytes --]

We are currently using 3.10.58 kernel and  we are facing this issue for samck enabled system.
and as we can check in other APIs like netlbl_sock_getattr and netlbl_conn_setattr have this preventive check so we added this check for netlbl_sock_delattr also.

And regarding patch re-submission, actually we have run checkpatch.pl before submission(successfull)  But when we submit the patch our editor changes tabs into space, we will resubmitt the patch ASAP.

Maninder Singh
------- Original Message -------
Sender : Casey Schaufler<casey@schaufler-ca.com>
Date : Mar 31, 2015 02:25 (GMT+09:00)
Title : Re: [Fix kernel crash in cipso_v4_sock_delattr ]

On 3/30/2015 4:32 AM, Paul Moore wrote:
> On Monday, March 30, 2015 11:09:00 AM Maninder Singh wrote:
>> Dear All,
>> we found One Kernel Crash issue in cipso_v4_sock_delattr :-
>> As Cipso supports only inet sockets so cipso_v4_sock_delattr will crash when
>> try to access any other socket type.  cipso_v4_sock_delattr access
>> sk_inet->inet_opt which may contain not NULL but invalid address. we found
>> this issue with netlink socket.(reproducible by trinity using sendto system
>> call .) 
> Hello,
>
> First, please go read the Documentation/SubmittingPatches from the kernel 
> sources; your patch needs to be resubmitted and the instructions in that file 
> will show you how to do it correctly next time.
>
> Second, this appears to only affect Smack based systems, yes?  SELinux based 
> systems should have the proper checking in place to prevent this (the checks 
> are handled in the LSM).

This looks like a problem that was fixed some time ago.
The current Smack code clearly checks for this. What kernel
version are you testing against?

> That said, it probably wouldn't hurt to add the 
> extra checking to netlbl_sock_delattr().  If you properly resubmit your patch 
> I'll ACK it.
>
> -Paul
>ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [Fix kernel crash in cipso_v4_sock_delattr ]
  2015-03-31  5:09 Re: [Fix kernel crash in cipso_v4_sock_delattr ] Maninder Singh
@ 2015-03-31 17:52 ` Casey Schaufler
  0 siblings, 0 replies; 3+ messages in thread
From: Casey Schaufler @ 2015-03-31 17:52 UTC (permalink / raw)
  To: maninder1.s, Paul Moore
  Cc: davem, netdev, linux-kernel, Vaneet Narang, AJEET YADAV, Casey Schaufler

On 3/30/2015 10:09 PM, Maninder Singh wrote:
> We are currently using 3.10.58 kernel and  we are facing this issue for samck enabled system.
> and as we can check in other APIs like netlbl_sock_getattr and netlbl_conn_setattr have this preventive check so we added this check for netlbl_sock_delattr also.
>
> And regarding patch re-submission, actually we have run checkpatch.pl before submission(successfull)  But when we submit the patch our editor changes tabs into space, we will resubmitt the patch ASAP.

Further review shows that the Smack code in 3.10.72 (I don't believe it changed
after 3.10.58) already checks for the address family being AF_INET. This would indicate
that the netlink code is sending garbage to security_socket_sendmsg().

Can you provide a more specific test case? I would like to see if this problem is
present in newer kernels.

>
> Maninder Singh
> ------- Original Message -------
> Sender : Casey Schaufler<casey@schaufler-ca.com>
> Date : Mar 31, 2015 02:25 (GMT+09:00)
> Title : Re: [Fix kernel crash in cipso_v4_sock_delattr ]
>
> On 3/30/2015 4:32 AM, Paul Moore wrote:
>> On Monday, March 30, 2015 11:09:00 AM Maninder Singh wrote:
>>> Dear All,
>>> we found One Kernel Crash issue in cipso_v4_sock_delattr :-
>>> As Cipso supports only inet sockets so cipso_v4_sock_delattr will crash when
>>> try to access any other socket type.  cipso_v4_sock_delattr access
>>> sk_inet->inet_opt which may contain not NULL but invalid address. we found
>>> this issue with netlink socket.(reproducible by trinity using sendto system
>>> call .) 
>> Hello,
>>
>> First, please go read the Documentation/SubmittingPatches from the kernel 
>> sources; your patch needs to be resubmitted and the instructions in that file 
>> will show you how to do it correctly next time.
>>
>> Second, this appears to only affect Smack based systems, yes?  SELinux based 
>> systems should have the proper checking in place to prevent this (the checks 
>> are handled in the LSM).
> This looks like a problem that was fixed some time ago.
> The current Smack code clearly checks for this. What kernel
> version are you testing against?
>
>> That said, it probably wouldn't hurt to add the 
>> extra checking to netlbl_sock_delattr().  If you properly resubmit your patch 
>> I'll ACK it.
>>
>> -Paul
>> N‹§²æìr¸›yúèšØb²X¬¶Ç§vØ^–)Þº{.nÇ+‰·¥Š{±‘êçzX§¶\x17›¡Ü¨}©ž²Æ zÚ&j:+v‰¨¾\a«‘êçzZ+€Ê+zf£¢·hšˆ§~†­†Ûiÿûàz¹\x1e®w¥¢¸?™¨è­Ú&¢)ߢ^[f”ù^jÇ«y§m…á@A«a¶Ú\x7fÿ\f0¶ìh®\x0få’i\x7f


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Re: [Fix kernel crash in cipso_v4_sock_delattr ]
@ 2015-04-01 13:07 Maninder Singh
  0 siblings, 0 replies; 3+ messages in thread
From: Maninder Singh @ 2015-04-01 13:07 UTC (permalink / raw)
  To: Casey Schaufler, Maninder Singh, Paul Moore
  Cc: davem, netdev, linux-kernel, Vaneet Narang, AJEET YADAV

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=windows-1252, Size: 3851 bytes --]

We have run trinity tool on smack enable system. like below:-

#./trinity -c sendto --dangerous
After some time we are able to crash the kernel:-

[<c04c8084>] (cipso_v4_sock_delattr+0x0/0x74) from [<c0517c44>] (netlbl_sock_delattr+0x18/0x1c)
 r4:00000000 r3:c07872f8
[<c0517c2c>] (netlbl_sock_delattr+0x0/0x1c) from [<c027b3e0>] (smack_netlabel+0x88/0x9c)
[<c027b358>] (smack_netlabel+0x0/0x9c) from [<c027b520>] (smack_netlabel_send+0x12c/0x144)
 r7:d9cee3c0 r6:d7b01ef4 r5:c076f408 r4:d88c84c0
[<c027b3f4>] (smack_netlabel_send+0x0/0x144) from [<c027b58c>] (smack_socket_sendmsg+0x54/0x60)
[<c027b538>] (smack_socket_sendmsg+0x0/0x60) from [<c0278ad0>] (security_socket_sendmsg+0x28/0x2c)
[<c0278aa8>] (security_socket_sendmsg+0x0/0x2c) from [<c0434490>] (sock_sendmsg+0x68/0xc0)
[<c0434428>] (sock_sendmsg+0x0/0xc0) from [<c0436ac8>] (SyS_sendto+0xd8/0x110)
 r7:01400118 r6:0000007f r5:da308a00 r4:c076f408
[<c04369f0>] (SyS_sendto+0x0/0x110) from [<c0012280>] (ret_fast_syscall+0x0/0x48)
Code: e5903200 e1a04000 e3530000 089da818 (e5d33016)
[SELP] while loop ... please attach T32...

And after further debugging we find this crash always come with Netlink socket.
And except thi API "netlbl_sock_delattr"  all other related Netlabel APIs have check to validate socket family.
Thats why we added socket family check for this API "netlbl_sock_delattr" and resolves our issue.

Thanks 
Maninder Singh

On 3/30/2015 10:09 PM, Maninder Singh wrote:
> We are currently using 3.10.58 kernel and  we are facing this issue for samck enabled system.
> and as we can check in other APIs like netlbl_sock_getattr and netlbl_conn_setattr have this preventive check so we added this check for netlbl_sock_delattr also.
>
> And regarding patch re-submission, actually we have run checkpatch.pl before submission(successfull)  But when we submit the patch our editor changes tabs into space, we will resubmitt the patch ASAP.

Further review shows that the Smack code in 3.10.72 (I don't believe it changed
after 3.10.58) already checks for the address family being AF_INET. This would indicate
that the netlink code is sending garbage to security_socket_sendmsg().

Can you provide a more specific test case? I would like to see if this problem is
present in newer kernels.

>
> Maninder Singh
> ------- Original Message -------
> Sender : Casey Schaufler
> Date : Mar 31, 2015 02:25 (GMT+09:00)
> Title : Re: [Fix kernel crash in cipso_v4_sock_delattr ]
>
> On 3/30/2015 4:32 AM, Paul Moore wrote:
>> On Monday, March 30, 2015 11:09:00 AM Maninder Singh wrote:
>>> Dear All,
>>> we found One Kernel Crash issue in cipso_v4_sock_delattr :-
>>> As Cipso supports only inet sockets so cipso_v4_sock_delattr will crash when
>>> try to access any other socket type.  cipso_v4_sock_delattr access
>>> sk_inet->inet_opt which may contain not NULL but invalid address. we found
>>> this issue with netlink socket.(reproducible by trinity using sendto system
>>> call .) 
>> Hello,
>>
>> First, please go read the Documentation/SubmittingPatches from the kernel 
>> sources; your patch needs to be resubmitted and the instructions in that file 
>> will show you how to do it correctly next time.
>>
>> Second, this appears to only affect Smack based systems, yes?  SELinux based 
>> systems should have the proper checking in place to prevent this (the checks 
>> are handled in the LSM).
> This looks like a problem that was fixed some time ago.
> The current Smack code clearly checks for this. What kernel
> version are you testing against?
>
>> That said, it probably wouldn't hurt to add the 
>> extra checking to netlbl_sock_delattr().  If you properly resubmit your patch 
>> I'll ACK it.
>>
>> -Paul
ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2015-04-01 13:07 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-03-31  5:09 Re: [Fix kernel crash in cipso_v4_sock_delattr ] Maninder Singh
2015-03-31 17:52 ` Casey Schaufler
2015-04-01 13:07 Maninder Singh

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).