Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Tue, 29 Jun 2010 20:43:39 -1000
From: akuster <akuster@...sta.com>
To: Eugene Teo <eugeneteo@...nel.sg>
CC: oss-security@...ts.openwall.com, 
 "Steven M. Christey" <coley@...us.mitre.org>
Subject: Re: CVE request - kernel: cifs: Fix a kernel BUG with
 remote OS/2 server


Eugene,

On 06/29/2010 02:02 PM, Eugene Teo wrote:
> On 06/30/2010 12:57 AM, akuster wrote:
>> pSMBr->CountHigh looks to have been introduce by commit
>> 381a420f5b23cedd9e166e052a93a7f4237bd57c back in 2.6.12-rc2.
>> So would it be said this issue has been around since then?
> 
> Which tree are you using? I got: fatal: bad object
> 381a420f5b23cedd9e166e052a93a7f4237bd57c.

I believe it is the historical git tree.
git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git

> 
> ->CountHigh was added long ago. Even v2.6.9 (rhel-4) is affected.
I don't see that in our 2.6.10 tree.

- Armin

> 
> Eugene
> 
>> On 06/27/2010 10:41 PM, Eugene Teo wrote:
>>> "This was known to trigger with a OS/2 server. The server sets
>>> pSMBr->CountHigh to a incorrect value even in case of normal writes.
>>> This results in 'nbytes' being computed wrongly and triggers a kernel
>>> BUG at mm/filemap.c.
>>>
>>>      void iov_iter_advance(struct iov_iter *i, size_t bytes)
>>>      {
>>>              BUG_ON(i->count<  bytes);<--- BUG here
>>>
>>> Why the server is setting 'CountHigh' is not clear but only does so
>>> after writing 64k bytes. Though this looks like the server bug, the
>>> client side crash may not be acceptable.
>>>
>>> The workaround is to mask off high 16 bits if the number of bytes
>>> written as returned by the server is greater than the bytes requested by
>>> the client."
>>>
>>> https://bugzilla.redhat.com/show_bug.cgi?id=608583
>>> http://git.kernel.org/linus/6513a81e9325d712f1bfb9a1d7b750134e49ff18
>>>
> 
> 

Powered by blists - more mailing lists

Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.