crash on read overflow

crash on read overflow

[Mkrtchyan, Tigran]

Hi Trond,

with RHEL6 kernel we observe kernel panic if server reply
more data than client requested. This is obviously fixed in
RHEL7 and upstream. Unfortunately, kernel crashes so badly
that I can't get any stacktrace. My guess is that
commit 64bd577ea0021f5903505de061b3b7d8a785ee94 is the one
which fixes the issue. Can you confirm?

Tigran.

Re: crash on read overflow

[Trond Myklebust]

Hi Tigran,

On Tue, Jun 16, 2015 at 6:08 AM, Mkrtchyan, Tigran
<tigran.mkrtchyan@desy.de> wrote:
>
>
> Hi Trond,
>
> with RHEL6 kernel we observe kernel panic if server reply
> more data than client requested. This is obviously fixed in
> RHEL7 and upstream. Unfortunately, kernel crashes so badly
> that I can't get any stacktrace. My guess is that
> commit 64bd577ea0021f5903505de061b3b7d8a785ee94 is the one
> which fixes the issue. Can you confirm?
>

That should help, but you also need to ensure that they have applied
commit bfeea1dc1c92 ("SUNRPC: Don't decode beyond the end of the RPC
reply message").

You might possibly also need commit 1537693ceaa8 ("SUNRPC: Clean up
xdr_set_iov()") and commit 76cacaabf15a ("SUNRPC: xdr_read_pages needs
to clear xdr->page_ptr.") since those are all dependencies for
bfeea1dc1c92.

Cheers
  Trond

Re: crash on read overflow

[Mkrtchyan, Tigran]

Hi Trond,

Yes, I already have discovered rpc level dependencies as well 
and testing a minnimal patch set for RHEL6.

Thanks,
  Tigran.

----- Original Message -----
> From: "Trond Myklebust" <trond.myklebust@primarydata.com>
> To: "Mkrtchyan, Tigran" <tigran.mkrtchyan@desy.de>
> Cc: "linux-nfs" <linux-nfs@vger.kernel.org>
> Sent: Tuesday, June 16, 2015 2:32:04 PM
> Subject: Re: crash on read overflow

> Hi Tigran,
> 
> On Tue, Jun 16, 2015 at 6:08 AM, Mkrtchyan, Tigran
> <tigran.mkrtchyan@desy.de> wrote:
>>
>>
>> Hi Trond,
>>
>> with RHEL6 kernel we observe kernel panic if server reply
>> more data than client requested. This is obviously fixed in
>> RHEL7 and upstream. Unfortunately, kernel crashes so badly
>> that I can't get any stacktrace. My guess is that
>> commit 64bd577ea0021f5903505de061b3b7d8a785ee94 is the one
>> which fixes the issue. Can you confirm?
>>
> 
> That should help, but you also need to ensure that they have applied
> commit bfeea1dc1c92 ("SUNRPC: Don't decode beyond the end of the RPC
> reply message").
> 
> You might possibly also need commit 1537693ceaa8 ("SUNRPC: Clean up
> xdr_set_iov()") and commit 76cacaabf15a ("SUNRPC: xdr_read_pages needs
> to clear xdr->page_ptr.") since those are all dependencies for
> bfeea1dc1c92.
> 
> Cheers
>  Trond
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: crash on read overflow

[Mkrtchyan, Tigran]

:( I added

c337d3655 SUNRPC: xdr_read_pages should return the amount of XDR encoded page data

But it still crashes.

Tigran.

----- Original Message -----
> From: "Mkrtchyan, Tigran" <tigran.mkrtchyan@desy.de>
> To: "Trond Myklebust" <trond.myklebust@primarydata.com>
> Cc: "linux-nfs" <linux-nfs@vger.kernel.org>
> Sent: Tuesday, June 16, 2015 3:05:23 PM
> Subject: Re: crash on read overflow

> Hi Trond,
> 
> Yes, I already have discovered rpc level dependencies as well
> and testing a minnimal patch set for RHEL6.
> 
> Thanks,
>  Tigran.
> 
> ----- Original Message -----
>> From: "Trond Myklebust" <trond.myklebust@primarydata.com>
>> To: "Mkrtchyan, Tigran" <tigran.mkrtchyan@desy.de>
>> Cc: "linux-nfs" <linux-nfs@vger.kernel.org>
>> Sent: Tuesday, June 16, 2015 2:32:04 PM
>> Subject: Re: crash on read overflow
> 
>> Hi Tigran,
>> 
>> On Tue, Jun 16, 2015 at 6:08 AM, Mkrtchyan, Tigran
>> <tigran.mkrtchyan@desy.de> wrote:
>>>
>>>
>>> Hi Trond,
>>>
>>> with RHEL6 kernel we observe kernel panic if server reply
>>> more data than client requested. This is obviously fixed in
>>> RHEL7 and upstream. Unfortunately, kernel crashes so badly
>>> that I can't get any stacktrace. My guess is that
>>> commit 64bd577ea0021f5903505de061b3b7d8a785ee94 is the one
>>> which fixes the issue. Can you confirm?
>>>
>> 
>> That should help, but you also need to ensure that they have applied
>> commit bfeea1dc1c92 ("SUNRPC: Don't decode beyond the end of the RPC
>> reply message").
>> 
>> You might possibly also need commit 1537693ceaa8 ("SUNRPC: Clean up
>> xdr_set_iov()") and commit 76cacaabf15a ("SUNRPC: xdr_read_pages needs
>> to clear xdr->page_ptr.") since those are all dependencies for
>> bfeea1dc1c92.
>> 
>> Cheers
>>  Trond
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
>> the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html