Messages in this thread | | | Subject | Re: [PATCH] virtio_ring: Fix mem leak with vring_new_virtqueue() | From | Jason Wang <> | Date | Wed, 26 Feb 2020 11:13:57 +0800 |
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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@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). > 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@redhat.com>
Thanks
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