This is a note to let you know that I've just added the patch titled
virtio: packed: fix unmap leak for indirect desc table
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
virtio-packed-fix-unmap-leak-for-indirect-desc-table.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 47661efa5a29226c88d8e50d26541550db629945
Author: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
Date: Fri Feb 23 15:18:33 2024 +0800
virtio: packed: fix unmap leak for indirect desc table
[ Upstream commit d5c0ed17fea60cca9bc3bf1278b49ba79242bbcd ]
When use_dma_api and premapped are true, then the do_unmap is false.
Because the do_unmap is false, vring_unmap_extra_packed is not called by
detach_buf_packed.
if (unlikely(vq->do_unmap)) {
curr = id;
for (i = 0; i < state->num; i++) {
vring_unmap_extra_packed(vq,
&vq->packed.desc_extra[curr]);
curr = vq->packed.desc_extra[curr].next;
}
}
So the indirect desc table is not unmapped. This causes the unmap leak.
So here, we check vq->use_dma_api instead. Synchronously, dma info is
updated based on use_dma_api judgment
This bug does not occur, because no driver use the premapped with
indirect.
Fixes: b319940f83c2 ("virtio_ring: skip unmap for premapped")
Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
Message-Id: <20240223071833.26095-1-xuanzhuo@xxxxxxxxxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 49299b1f9ec74..6f7e5010a6735 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1340,7 +1340,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
sizeof(struct vring_packed_desc));
vq->packed.vring.desc[head].id = cpu_to_le16(id);
- if (vq->do_unmap) {
+ if (vq->use_dma_api) {
vq->packed.desc_extra[id].addr = addr;
vq->packed.desc_extra[id].len = total_sg *
sizeof(struct vring_packed_desc);
@@ -1481,7 +1481,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
desc[i].len = cpu_to_le32(sg->length);
desc[i].id = cpu_to_le16(id);
- if (unlikely(vq->do_unmap)) {
+ if (unlikely(vq->use_dma_api)) {
vq->packed.desc_extra[curr].addr = addr;
vq->packed.desc_extra[curr].len = sg->length;
vq->packed.desc_extra[curr].flags =
@@ -1615,7 +1615,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
vq->free_head = id;
vq->vq.num_free += state->num;
- if (unlikely(vq->do_unmap)) {
+ if (unlikely(vq->use_dma_api)) {
curr = id;
for (i = 0; i < state->num; i++) {
vring_unmap_extra_packed(vq,
