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* [PATCH] virtio_ring: Fix mem leak with vring_new_virtqueue()
@ 2020-02-24 21:26 Suman Anna
  2020-02-25  5:39 ` Jason Wang
  0 siblings, 1 reply; 7+ messages in thread
From: Suman Anna @ 2020-02-24 21:26 UTC (permalink / raw)
  To: Michael S. Tsirkin, Jason Wang
  Cc: Tiwei Bie, David S. Miller, virtualization, linux-kernel,
	linux-remoteproc, Suman Anna

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@ti.com>
---
 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);
 	list_del(&_vq->list);
 	kfree(vq);
 }
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2020-03-08  7:58 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-24 21:26 [PATCH] virtio_ring: Fix mem leak with vring_new_virtqueue() Suman Anna
2020-02-25  5:39 ` Jason Wang
2020-02-25 16:51   ` Suman Anna
2020-02-26  3:13     ` Jason Wang
2020-02-26 17:01       ` Suman Anna
2020-03-06  0:27       ` Suman Anna
2020-03-08  7:58         ` Michael S. Tsirkin

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