On 2020/2/26 上午12:51, Suman Anna wrote:
Hi Jason,
On 2/24/20 11:39 PM, Jason Wang wrote:
On 2020/2/25 上午5:26, Suman Anna wrote:
The functions vring_new_virtqueue() and __vring_new_virtqueue() are used
with split rings, and any allocations within these functions are managed
outside of the .we_own_ring flag. The commit cbeedb72b97a ("virtio_ring:
allocate desc state for split ring separately") allocates the desc state
within the __vring_new_virtqueue() but frees it only when the
.we_own_ring
flag is set. This leads to a memory leak when freeing such allocated
virtqueues with the vring_del_virtqueue() function.
Fix this by moving the desc_state free code outside the flag and only
for split rings. Issue was discovered during testing with remoteproc
and virtio_rpmsg.
Fixes: cbeedb72b97a ("virtio_ring: allocate desc state for split ring
separately")
Signed-off-by: Suman Anna<s-anna@xxxxxx>
---
drivers/virtio/virtio_ring.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 867c7ebd3f10..58b96baa8d48 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2203,10 +2203,10 @@ void vring_del_virtqueue(struct virtqueue *_vq)
vq->split.queue_size_in_bytes,
vq->split.vring.desc,
vq->split.queue_dma_addr);
-
- kfree(vq->split.desc_state);
}
}
+ if (!vq->packed_ring)
+ kfree(vq->split.desc_state);
Nitpick, it looks to me it would be more clear if we just free
desc_state unconditionally here (and remove the kfree for packed above).
OK, are you sure you want that to be folded into this patch? It looks to
me a separate cleanup/consolidation patch, and packed desc_state does
not suffer this memleak, and need not be backported into stable kernels.
regards
Suman
Though it's just a small tweak, I'm fine for leaving it for future.
So
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Thanks
