I can't immediately see how that patch would fix it (I wrote it). When dropbear fails does it log anything in auth.log?

Cheers,
Matt

On 21 September 2015 4:03:24 pm AWST, Madper Xie <email address hidden> wrote:
>Public bug reported:
>
>I'm connecting via ssh to our platform running dropbear. If I cat
>/var/log/syslog, I'm seeing the connection break with the following:
>Write failed: Broken pipe
>
>The syslog is about 2MB size.
>
>I can reproduce the issue in ubuntu 14.04.3.
>The version of dropbear is 2013.60-1ubuntu2.1
>
>`xxd /dev/zero` can reproduce the issue 100%.
>
>[Impact]
>
> * In fact it is really an annoying bug due to I can't visit my syslog
>or other large file via cat.
>
>[Test Case]
>The minimum reproducer should be:
> * system A running a dropbear as a ssh server.
> * ssh username@systemA from system B. (A and B should be different
>computer.)
> * xxd /dev/zero
> * the connection will be broken.
>
>[Regression Potential]
> * I find the patch from upstream. And it already been merged. So I
>think it's safe to merge it into ubuntu.
>
>[Other Info]
> * The latest dropbear-2015.68 can't reproduce the issue.
> * After a bisect I find this patch fixed the issue:
>https://github.com/mkj/dropbear/commit/db688e3
> * There is a bit conflict if you apply above commit. The fixed version
>is attached.
>
>** Affects: dropbear (Ubuntu)
>     Importance: Undecided
>         Status: New
>
>** Patch added: "test.patch"
>https://bugs.launchpad.net/bugs/1497883/+attachment/4470114/+files/test.patch
>
>** Description changed:
>
>I'm connecting via ssh to our platform running dropbear. If I cat
>/var/log/syslog, I'm seeing the connection break with the following:
>  Write failed: Broken pipe
>  
>  The syslog is about 2MB size.
>+ 
>+ I can reproduce the issue in ubuntu 14.04.3.
>+ The version of dropbear is 2013.60-1ubuntu2.1
>+ 
>  `xxd /dev/zero` can reproduce the issue 100%.
>- [Impact] 
>  
>-  * In fact it is really an annoying bug due to I can't visit my
>syslog
>+ [Impact]
>+ 
>+  * In fact it is really an annoying bug due to I can't visit my
>syslog
>  or other large file via cat.
>  
>  [Test Case]
>  The minimum reproducer should be:
>-  * system A running a dropbear as a ssh server.
>-  * ssh username@systemA from system B. (A and B should be different
>computer.)
>-  * xxd /dev/zero
>-  * the connection will be broken.
>+  * system A running a dropbear as a ssh server.
>+  * ssh username@systemA from system B. (A and B should be different
>computer.)
>+  * xxd /dev/zero
>+  * the connection will be broken.
>  
>- [Regression Potential] 
>-  * I find the patch from upstream. And it already been merged. So I
>think it's safe to merge it into ubuntu.
>+ [Regression Potential]
>+  * I find the patch from upstream. And it already been merged. So I
>think it's safe to merge it into ubuntu.
>  
>  [Other Info]
>-  * The latest dropbear-2015.68 can't reproduce the issue.
>-  * After a bisect I find this patch fixed the issue:
>https://github.com/mkj/dropbear/commit/db688e3
>-  * There is a bit conflict if you apply above commit. The fixed
>version is attached.
>+  * The latest dropbear-2015.68 can't reproduce the issue.
>+  * After a bisect I find this patch fixed the issue:
>https://github.com/mkj/dropbear/commit/db688e3
>+  * There is a bit conflict if you apply above commit. The fixed
>version is attached.