[RFC PATCH] lsm,fs: fix vfs_getxattr_alloc() return type and caller error paths

[Paul Moore]

On Thu, Nov 17, 2022 at 8:54 PM Serge E. Hallyn <serge at hallyn.com> wrote:
> On Wed, Nov 09, 2022 at 11:36:14PM -0500, Paul Moore wrote:
> > The vfs_getxattr_alloc() function currently returns a ssize_t value
> > despite the fact that it only uses int values internally for return
> > values.  Fix this by converting vfs_getxattr_alloc() to return an
> > int type and adjust the callers as necessary.  As part of these
> > caller modifications, some of the callers are fixed to properly free
> > the xattr value buffer on both success and failure to ensure that
> > memory is not leaked in the failure case.
> >
> > Signed-off-by: Paul Moore <paul at paul-moore.com>
>
> Reviewed-by: Serge Hallyn <serge at hallyn.com>
>
> Do I understand right that the change to process_measurement()
> will avoid an unnecessary call to krealloc() if the xattr has
> not changed size between the two calls to ima_read_xattr()?
> If something more than that is going on there, it might be
> worth pointing out in the commit message.

Yes, that was the intent, trying to avoid extra calls to krealloc().

Mimi, have you had a chance to look at this patch yet?  In addition to
cleaning up the vfs_getxattr_alloc() function it resolves some issues
with IMA (memory leaks), but as you're the IMA expert I really need
your review on this ...

-- 
paul-moore.com