Messages in this thread | | | Subject | Re: [050/107] block: check for proper length of iov entries earlier in blk_rq_map_user_iov() | From | Ben Hutchings <> | Date | Fri, 04 Nov 2011 15:24:16 +0000 |
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On Wed, 2011-11-02 at 15:14 -0700, Greg KH wrote: > 2.6.32-longterm review patch. If anyone has any objections, please let us know. > > ------------------ > > From: Xiaotian Feng <dfeng@redhat.com> > > commit 5478755616ae2ef1ce144dded589b62b2a50d575 upstream. > > commit 9284bcf checks for proper length of iov entries in > blk_rq_map_user_iov(). But if the map is unaligned, kernel > will break out the loop without checking for the proper length. > So we need to check the proper length before the unalign check.
This will catch an unaligned zero-length entry. But there's still no check for zero-length iov entries *after* the unaligned entry.
[...] > --- a/block/blk-map.c > +++ b/block/blk-map.c > @@ -201,12 +201,13 @@ int blk_rq_map_user_iov(struct request_q > for (i = 0; i < iov_count; i++) { > unsigned long uaddr = (unsigned long)iov[i].iov_base; > > + if (!iov[i].iov_len) > + return -EINVAL; > + > if (uaddr & queue_dma_alignment(q)) { > unaligned = 1; > break;
I think the correct fix is just to remove the 'break'.
Ben.
> } > - if (!iov[i].iov_len) > - return -EINVAL; > } > > if (unaligned || (q->dma_pad_mask & len) || map_data) >
-- Ben Hutchings Sturgeon's Law: Ninety percent of everything is crap. [unhandled content-type:application/pgp-signature] | |