diff options
| author | Jens Axboe <jaxboe@fusionio.com> | 2010-10-29 11:31:42 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-12-09 13:26:30 -0800 |
| commit | 239023a9d11fa1be4fec0adc4d9b840c4b815775 (patch) | |
| tree | d8f7b0beee212dfd422c1eb8a605a80a0365a1ee /block | |
| parent | 870cd3681836a2e822090522c8cb6fce19cf9e5c (diff) | |
block: take care not to overflow when calculating total iov length
commit 9f864c80913467312c7b8690e41fb5ebd1b50e92 upstream.
Reported-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'block')
| -rw-r--r-- | block/scsi_ioctl.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index e5b10017a50..1d5a7805446 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -319,33 +319,47 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk, if (hdr->iovec_count) { const int size = sizeof(struct sg_iovec) * hdr->iovec_count; size_t iov_data_len; - struct sg_iovec *iov; + struct sg_iovec *sg_iov; + struct iovec *iov; + int i; - iov = kmalloc(size, GFP_KERNEL); - if (!iov) { + sg_iov = kmalloc(size, GFP_KERNEL); + if (!sg_iov) { ret = -ENOMEM; goto out; } - if (copy_from_user(iov, hdr->dxferp, size)) { - kfree(iov); + if (copy_from_user(sg_iov, hdr->dxferp, size)) { + kfree(sg_iov); ret = -EFAULT; goto out; } + /* + * Sum up the vecs, making sure they don't overflow + */ + iov = (struct iovec *) sg_iov; + iov_data_len = 0; + for (i = 0; i < hdr->iovec_count; i++) { + if (iov_data_len + iov[i].iov_len < iov_data_len) { + kfree(sg_iov); + ret = -EINVAL; + goto out; + } + iov_data_len += iov[i].iov_len; + } + /* SG_IO howto says that the shorter of the two wins */ - iov_data_len = iov_length((struct iovec *)iov, - hdr->iovec_count); if (hdr->dxfer_len < iov_data_len) { - hdr->iovec_count = iov_shorten((struct iovec *)iov, + hdr->iovec_count = iov_shorten(iov, hdr->iovec_count, hdr->dxfer_len); iov_data_len = hdr->dxfer_len; } - ret = blk_rq_map_user_iov(q, rq, NULL, iov, hdr->iovec_count, + ret = blk_rq_map_user_iov(q, rq, NULL, sg_iov, hdr->iovec_count, iov_data_len, GFP_KERNEL); - kfree(iov); + kfree(sg_iov); } else if (hdr->dxfer_len) ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len, GFP_KERNEL); |