block: check for proper length of iov entries earlier in blk_rq_map_user_iov()

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.

Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
Xiaotian Feng 2010-11-29 10:03:55 +01:00 committed by Jens Axboe
parent a115413de1
commit 5478755616

View File

@ -201,12 +201,13 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
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;
}
if (!iov[i].iov_len)
return -EINVAL;
}
if (unaligned || (q->dma_pad_mask & len) || map_data)