Re: gfs2_fh_to_parent() array overflow

From: Adrian Bunk
Date: Wed Feb 13 2008 - 16:50:47 EST


On Mon, Oct 29, 2007 at 09:11:21AM +0000, Steven Whitehouse wrote:
> Hi,
>
> On Sat, 2007-10-27 at 23:00 +0200, Christoph Hellwig wrote:
> > On Wed, Oct 24, 2007 at 06:26:26PM +0200, Adrian Bunk wrote:
> > > The Coverity checker spotted the following array overflow caused by
> > > commit 34c0d154243dd913c5690ae6ceb9557017429b9c:
> >
> > The line is a left-over from times when gfs stored the mode of the
> > inode in the file handle. It can simply be deleted. Steve, do you
> > want a patch for that or could you commit that one-liner directly?
> >
>
> I'm just back from holiday this morning and this is looking a bit more
> complicated than that... give me a day or two and I'll try and come up
> with a solution,

This issue is still present in 2.6.25-rc1.

> Steve.
>
> > > fs/gfs2/ops_export.c contains:
> > >
> > > <-- snip -->
> > >
> > > ...
> > > static struct dentry *gfs2_fh_to_parent(struct super_block *sb, struct fid *fid,
> > > int fh_len, int fh_type)
> > > {
> > > struct gfs2_inum_host parent;
> > > __be32 *fh = (__force __be32 *)fid->raw; <------------
> > >
> > > switch (fh_type) {
> > > case GFS2_LARGE_FH_SIZE:
> > > case GFS2_OLD_FH_SIZE:
> > > parent.no_formal_ino = ((u64)be32_to_cpu(fh[4])) << 32;
> > > parent.no_formal_ino |= be32_to_cpu(fh[5]);
> > > parent.no_addr = ((u64)be32_to_cpu(fh[6])) << 32;
> > > ^^^^^
> > > parent.no_addr |= be32_to_cpu(fh[7]);
> > > ... ^^^^^
> > >
> > > <-- snip -->
> > >
> > >
> > > cu
> > > Adrian
> > >

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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