Messages in this thread | | | Subject | Re: [PATCH] virtio_ring: Fix mem leak with vring_new_virtqueue() | From | Jason Wang <> | Date | Tue, 25 Feb 2020 13:39:41 +0800 |
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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@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);
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).
Anyway desc_state will be allocated by use even if !we_own_ring.
Thanks
> list_del(&_vq->list); > kfree(vq); > }
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