Commit-ID: 9519954ee80e49221f57ae389636e3b010c4f437
Gitweb: http://git.kernel.org/tip/9519954ee80e49221f57ae389636e3b010c4f437
Author: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
AuthorDate: Sun, 19 Jun 2011 15:14:35 +0530
Committer: Sasha Levin <levinsasha928@xxxxxxxxx>
CommitDate: Sun, 19 Jun 2011 17:28:19 -0400
tools/kvm/9p: check the iov count with the read/write count
Make sure we don't read/write more than what is requested
from client.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
---
tools/kvm/virtio/9p.c | 21 +++++++++++++++++++++
1 files changed, 21 insertions(+), 0 deletions(-)
diff --git a/tools/kvm/virtio/9p.c b/tools/kvm/virtio/9p.c
index 24acb58..d27017b 100644
--- a/tools/kvm/virtio/9p.c
+++ b/tools/kvm/virtio/9p.c
@@ -194,6 +194,22 @@ static void set_p9msg_hdr(struct p9_msg *msg, u32 size, u8 cmd, u16 tag)
};
}
+static u16 virtio_p9_update_iov_cnt(struct iovec iov[], u32 count, int iov_cnt)
+{
+ int i;
+ u32 total = 0;
+ for (i = 0; (i < iov_cnt) && (total < count); i++) {
+ if (total + iov[i].iov_len > count) {
+ /* we don't need this iov fully */
+ iov[i].iov_len -= ((total + iov[i].iov_len) - count);
+ i++;
+ break;
+ }
+ total += iov[i].iov_len;
+ }
+ return i;
+}
+
static bool virtio_p9_version(struct p9_dev *p9dev,
struct p9_pdu *pdu, u32 *outlen)
{
@@ -445,6 +461,9 @@ static bool virtio_p9_read(struct p9_dev *p9dev,
} else {
pdu->in_iov[0].iov_base += VIRTIO_P9_HDR_LEN + sizeof(u32);
pdu->in_iov[0].iov_len -= VIRTIO_P9_HDR_LEN + sizeof(u32);
+ pdu->in_iov_cnt = virtio_p9_update_iov_cnt(pdu->in_iov,
+ tread->count,
+ pdu->in_iov_cnt);
rread->count = preadv(fid->fd, pdu->in_iov,
pdu->in_iov_cnt, tread->offset);
if (rread->count > tread->count)
@@ -549,6 +568,8 @@ static bool virtio_p9_write(struct p9_dev *p9dev,
pdu->out_iov[0].iov_base += (sizeof(*outmsg) + sizeof(*twrite));
pdu->out_iov[0].iov_len -= (sizeof(*outmsg) + sizeof(*twrite));
+ pdu->out_iov_cnt = virtio_p9_update_iov_cnt(pdu->out_iov, twrite->count,
+ pdu->out_iov_cnt);
rwrite->count = pwritev(fid->fd, pdu->out_iov,
pdu->out_iov_cnt, twrite->offset);
*outlen = VIRTIO_P9_HDR_LEN + sizeof(u32);
--
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