2015-06-16 10:08:58

by Mkrtchyan, Tigran

[permalink] [raw]
Subject: crash on read overflow



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.



2015-06-16 12:32:06

by Trond Myklebust

[permalink] [raw]
Subject: Re: crash on read overflow

Hi Tigran,

On Tue, Jun 16, 2015 at 6:08 AM, Mkrtchyan, Tigran
<[email protected]> 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

2015-06-16 13:05:25

by Mkrtchyan, Tigran

[permalink] [raw]
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" <[email protected]>
> To: "Mkrtchyan, Tigran" <[email protected]>
> Cc: "linux-nfs" <[email protected]>
> 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
> <[email protected]> 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 [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

2015-06-16 14:24:01

by Mkrtchyan, Tigran

[permalink] [raw]
Subject: Re: crash on read overflow

:( 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" <[email protected]>
> To: "Trond Myklebust" <[email protected]>
> Cc: "linux-nfs" <[email protected]>
> 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" <[email protected]>
>> To: "Mkrtchyan, Tigran" <[email protected]>
>> Cc: "linux-nfs" <[email protected]>
>> 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
>> <[email protected]> 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 [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html