From abd764250fbce6f285513d74f03eb5c526e520f6 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Wed, 9 Jul 2014 10:05:47 +0200 Subject: dataplane: do not free VirtQueueElement in vring_push() VirtQueueElement is allocated in vring_pop() so it seems to make sense that vring_push() should free it. Alas, virtio-blk frees VirtQueueElement itself in virtio_blk_free_request(). This patch solves a double-free assertion in glib's g_slice_free(). Rename vring_free_element() to vring_unmap_element() since it no longer frees the VirtQueueElement. Signed-off-by: Stefan Hajnoczi Tested-by: Christian Borntraeger Signed-off-by: Kevin Wolf --- hw/virtio/dataplane/vring.c | 9 ++++----- include/hw/virtio/dataplane/vring.h | 1 - 2 files changed, 4 insertions(+), 6 deletions(-) diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c index 665a1ff..5d17d39 100644 --- a/hw/virtio/dataplane/vring.c +++ b/hw/virtio/dataplane/vring.c @@ -272,7 +272,7 @@ static int get_indirect(Vring *vring, VirtQueueElement *elem, return 0; } -void vring_free_element(VirtQueueElement *elem) +static void vring_unmap_element(VirtQueueElement *elem) { int i; @@ -287,8 +287,6 @@ void vring_free_element(VirtQueueElement *elem) for (i = 0; i < elem->in_num; i++) { vring_unmap(elem->in_sg[i].iov_base, true); } - - g_slice_free(VirtQueueElement, elem); } /* This looks in the virtqueue and for the first available buffer, and converts @@ -402,7 +400,8 @@ out: vring->broken = true; } if (elem) { - vring_free_element(elem); + vring_unmap_element(elem); + g_slice_free(VirtQueueElement, elem); } *p_elem = NULL; return ret; @@ -418,7 +417,7 @@ void vring_push(Vring *vring, VirtQueueElement *elem, int len) unsigned int head = elem->index; uint16_t new; - vring_free_element(elem); + vring_unmap_element(elem); /* Don't touch vring if a fatal error occurred */ if (vring->broken) { diff --git a/include/hw/virtio/dataplane/vring.h b/include/hw/virtio/dataplane/vring.h index 63e7bf4..b23edd2 100644 --- a/include/hw/virtio/dataplane/vring.h +++ b/include/hw/virtio/dataplane/vring.h @@ -55,6 +55,5 @@ bool vring_enable_notification(VirtIODevice *vdev, Vring *vring); bool vring_should_notify(VirtIODevice *vdev, Vring *vring); int vring_pop(VirtIODevice *vdev, Vring *vring, VirtQueueElement **elem); void vring_push(Vring *vring, VirtQueueElement *elem, int len); -void vring_free_element(VirtQueueElement *elem); #endif /* VRING_H */ -- cgit v1.1