Re: [Xen-devel] [PATCH] make pygrub cope better with big files in guest

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Wed, 2012-05-16 at 08:25 +0100, M A Young wrote:
> On Wed, 16 May 2012, M A Young wrote:
> 
> > Pygrub can use a lot of memory if the kernel or ramdisk files in a guest 
> > are 
> > very big as it reads them into memory before writing them out again to 
> > temporary files (these can legitimately be big for example the initrd.img 
> > file in a Fedora 16 install is around 130MB ).
> >
> > This patch allows these files to be copied in one megabyte pieces, and if 
> > it 
> > sees any write problems it delets the files and exits. It also only reads 
> > up 
> > to the first megabyte of configurations files for grub etc. to avoid 
> > problems 
> > here as well (as it is a text file it should actually be much smaller).
> >
> > This issue was reported by Xinli Niu in the Fedora bug report
> > https://bugzilla.redhat.com/show_bug.cgi?id=818412 who got it a CVE 
> > reference 
> > CVE-2012-2625 .
> 
> I realized the first patch was flawed as I was potentially using a file 
> descriptor after I closed it. This is an untested correction.

I think you might want a couple of closes on datafile in here. Otherwise
it looks good to me (by inspection, I've not run it either).

Thanks!

Ian.


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