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authorStefano Garzarella <sgarzare@redhat.com>2020-10-08 22:42:56 +0200
committerMichael S. Tsirkin <mst@redhat.com>2020-10-21 10:38:45 -0400
commit5745bcfbbf89b158416075374254d3c013488f21 (patch)
tree597ae1966131a3c7715c1ca972d9957db456c917
parent1897f0b618b0af0eb9dca709ab6bdf9ef1969ef7 (diff)
vringh: fix __vringh_iov() when riov and wiov are different
If riov and wiov are both defined and they point to different objects, only riov is initialized. If the wiov is not initialized by the caller, the function fails returning -EINVAL and printing "Readable desc 0x... after writable" error message. This issue happens when descriptors have both readable and writable buffers (eg. virtio-blk devices has virtio_blk_outhdr in the readable buffer and status as last byte of writable buffer) and we call __vringh_iov() to get both type of buffers in two different iovecs. Let's replace the 'else if' clause with 'if' to initialize both riov and wiov if they are not NULL. As checkpatch pointed out, we also avoid crashing the kernel when riov and wiov are both NULL, replacing BUG() with WARN_ON() and returning -EINVAL. Fixes: f87d0fbb5798 ("vringh: host-side implementation of virtio rings.") Cc: stable@vger.kernel.org Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/r/20201008204256.162292-1-sgarzare@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
-rw-r--r--drivers/vhost/vringh.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index e059a9a47cdf..8bd8b403f087 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -284,13 +284,14 @@ __vringh_iov(struct vringh *vrh, u16 i,
desc_max = vrh->vring.num;
up_next = -1;
+ /* You must want something! */
+ if (WARN_ON(!riov && !wiov))
+ return -EINVAL;
+
if (riov)
riov->i = riov->used = 0;
- else if (wiov)
+ if (wiov)
wiov->i = wiov->used = 0;
- else
- /* You must want something! */
- BUG();
for (;;) {
void *addr;