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authorMichael S. Tsirkin <mst@redhat.com>2010-07-26 16:55:30 +0930
committerLinus Torvalds <torvalds@linux-foundation.org>2010-07-26 08:05:31 -0700
commit1fe9b6fef11771461e69ecd1bc8935a1c7c90cb5 (patch)
tree3ecc82deed99dc11c67d64bfea2737fc68d769d3
parent2e65a2075cc740b485ab203430bdf3459d5551b6 (diff)
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virtio: fix oops on OOM
virtio ring was changed to return an error code on OOM, but one caller was missed and still checks for vq->vring.num. The fix is just to check for <0 error code. Long term it might make sense to change goto add_head to just return an error on oom instead, but let's apply a minimal fix for 2.6.35. Reported-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Tested-by: Chris Mason <chris.mason@oracle.com> Cc: stable@kernel.org # .34.x Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/virtio/virtio_ring.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index afe7e21dd0a..1475ed6b575 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -164,7 +164,8 @@ int virtqueue_add_buf_gfp(struct virtqueue *_vq,
gfp_t gfp)
{
struct vring_virtqueue *vq = to_vvq(_vq);
- unsigned int i, avail, head, uninitialized_var(prev);
+ unsigned int i, avail, uninitialized_var(prev);
+ int head;
START_USE(vq);
@@ -174,7 +175,7 @@ int virtqueue_add_buf_gfp(struct virtqueue *_vq,
* buffers, then go indirect. FIXME: tune this threshold */
if (vq->indirect && (out + in) > 1 && vq->num_free) {
head = vring_add_indirect(vq, sg, out, in, gfp);
- if (head != vq->vring.num)
+ if (likely(head >= 0))
goto add_head;
}