Re: Re: [Fix kernel crash in cipso_v4_sock_delattr ]

From: Maninder Singh
Date: Tue Mar 31 2015 - 01:10:19 EST


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@xxxxxxxxxxxxxxxx>
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
>