[Cluster-devel] cluster: RHEL6 - fsck.gfs2: Fix buffer overflow in get_lockproto_table

[Cluster-devel] cluster: RHEL6 - fsck.gfs2: Fix buffer overflow in get_lockproto_table

[Fabio M. Di Nitto]

On 08/16/2012 11:01 PM, Andrew Price wrote:
> Gitweb:        http://git.fedorahosted.org/git/?p=cluster.git;a=commitdiff;h=f796ee8752712e9e523e1516bb9165b274552753
> Commit:        f796ee8752712e9e523e1516bb9165b274552753
> Parent:        638deec0ccbf45862eee97294f09ba9d6b3f56d0
> Author:        Andrew Price <anprice@redhat.com>
> AuthorDate:    Sat Jul 7 22:03:24 2012 +0100
> Committer:     Andrew Price <anprice@redhat.com>
> CommitterDate: Thu Aug 16 21:54:56 2012 +0100
> 
> fsck.gfs2: Fix buffer overflow in get_lockproto_table
> 
> Coverity discovered a buffer overflow in this function where an overly
> long cluster name in cluster.conf could cause a crash while repairing
> the superblock. This patch fixes the bug by making sure the lock table
> is composed sensibly, limiting the fsname to 16 chars as documented, and
> only allowing the cluster name (which doesn't seem to have a documented
> max size) to use the remaining space in the locktable name string.

cluster name is max 16 bytes too (including \0). It's actually verified
by cman at startup so it can't be longer than that.

Fabio

[Cluster-devel] cluster: RHEL6 - fsck.gfs2: Fix buffer overflow in get_lockproto_table

[Andrew Price]

On 17/08/12 05:02, Fabio M. Di Nitto wrote:
> On 08/16/2012 11:01 PM, Andrew Price wrote:
>> Gitweb:        http://git.fedorahosted.org/git/?p=cluster.git;a=commitdiff;h=f796ee8752712e9e523e1516bb9165b274552753
>> Commit:        f796ee8752712e9e523e1516bb9165b274552753
>> Parent:        638deec0ccbf45862eee97294f09ba9d6b3f56d0
>> Author:        Andrew Price <anprice@redhat.com>
>> AuthorDate:    Sat Jul 7 22:03:24 2012 +0100
>> Committer:     Andrew Price <anprice@redhat.com>
>> CommitterDate: Thu Aug 16 21:54:56 2012 +0100
>>
>> fsck.gfs2: Fix buffer overflow in get_lockproto_table
>>
>> Coverity discovered a buffer overflow in this function where an overly
>> long cluster name in cluster.conf could cause a crash while repairing
>> the superblock. This patch fixes the bug by making sure the lock table
>> is composed sensibly, limiting the fsname to 16 chars as documented, and
>> only allowing the cluster name (which doesn't seem to have a documented
>> max size) to use the remaining space in the locktable name string.
>
> cluster name is max 16 bytes too (including \0). It's actually verified
> by cman at startup so it can't be longer than that.

OK, thanks for clearing that up. There are other places in gfs2-utils 
which we can tighten up now that we know that the cluster name has a 
solid limit so I'm going to push this patch (which fixes the overflow 
bug) and we'll address the limit issues separately.

BTW, now that cman has disappeared upstream is anything checking the 
length of the cluster name now?

Andy

[Cluster-devel] cluster: RHEL6 - fsck.gfs2: Fix buffer overflow in get_lockproto_table

[Fabio M. Di Nitto]

On 8/17/2012 11:57 AM, Andrew Price wrote:
> On 17/08/12 05:02, Fabio M. Di Nitto wrote:
>> On 08/16/2012 11:01 PM, Andrew Price wrote:
>>> Gitweb:       
>>> http://git.fedorahosted.org/git/?p=cluster.git;a=commitdiff;h=f796ee8752712e9e523e1516bb9165b274552753
>>>
>>> Commit:        f796ee8752712e9e523e1516bb9165b274552753
>>> Parent:        638deec0ccbf45862eee97294f09ba9d6b3f56d0
>>> Author:        Andrew Price <anprice@redhat.com>
>>> AuthorDate:    Sat Jul 7 22:03:24 2012 +0100
>>> Committer:     Andrew Price <anprice@redhat.com>
>>> CommitterDate: Thu Aug 16 21:54:56 2012 +0100
>>>
>>> fsck.gfs2: Fix buffer overflow in get_lockproto_table
>>>
>>> Coverity discovered a buffer overflow in this function where an overly
>>> long cluster name in cluster.conf could cause a crash while repairing
>>> the superblock. This patch fixes the bug by making sure the lock table
>>> is composed sensibly, limiting the fsname to 16 chars as documented, and
>>> only allowing the cluster name (which doesn't seem to have a documented
>>> max size) to use the remaining space in the locktable name string.
>>
>> cluster name is max 16 bytes too (including \0). It's actually verified
>> by cman at startup so it can't be longer than that.
> 
> OK, thanks for clearing that up. There are other places in gfs2-utils
> which we can tighten up now that we know that the cluster name has a
> solid limit so I'm going to push this patch (which fixes the overflow
> bug) and we'll address the limit issues separately.
> 
> BTW, now that cman has disappeared upstream is anything checking the
> length of the cluster name now?

I am not sure. I don?t think corosync enforces any limit, but best to
check with Jan.

Fabio