Re: Re: apache 2.4 directory autoindex corrupted

[Kurtis Rader <krader@xxxxxxxxxxxxx>]

On Mon, Oct 26, 2015 at 7:41 PM, Jan Schaumann <jschauma@xxxxxxxxxxxxxx> wrote:

Jan Schaumann <jschauma@xxxxxxxxxxxxxx> wrote:

> I just upgraded apache 2.2 to apache 2.4.  After the upgrade, my
> autoindex directory listings show up as corrupted strings (see
> https://www.netmeister.org/t/ for an example).  All other content
> serving appears to work fine.

It turns out I was wrong.  All other content gets appended null bytes
until the size is a multiple of 2K, which happens to be my file system's
fragsize.  It seems, somehow apache is getting the wrong filesize for
all files and directories such that instead of getting the actual
filesize, it gets the filesize in blocks:

...

Any idea how this might happen?

My first guess is that you've enabled memory-mapping of content. See the EnableMMAP directive: http://httpd.apache.org/docs/current/mod/core.html#enablemmap

The documentation for that option doesn't describe the problem you reported. But incorrectly implementing memory-mapping would cause the type of problem you're seeing. On the other hand autoindex directory listings do not normally involve mmap'ing static files. So I suspect there is something unusual about your apache config that worked fine, possibly by accident, under version 2.2 and results in incorrect output under version 2.4. Are you using any third-party modules? Can you employ a "divide and conquer" debug strategy to eliminate possible causes of the problem?

--

Kurtis Rader

Caretaker of the exceptional canines Junior and Hank