[PATCH] vfio: Fix double free for caps->buf

[Schspa Shi <schspa@xxxxxxxxx>]

There is a double free, if vfio_iommu_dma_avail_build_caps
calls failed.

The following call path will call vfio_info_cap_add multiple times

vfio_iommu_type1_get_info
	if (!ret)
		ret = vfio_iommu_dma_avail_build_caps(iommu, &caps);

	if (!ret)
		ret = vfio_iommu_iova_build_caps(iommu, &caps);

If krealloc failed on vfio_info_cap_add, there will be a double free.

Signed-off-by: Schspa Shi <schspa@xxxxxxxxx>
---
 drivers/vfio/vfio.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 61e71c1154be..a0fb93866f61 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1812,6 +1812,7 @@ struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
 	buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
 	if (!buf) {
 		kfree(caps->buf);
+		caps->buf = NULL;
 		caps->size = 0;
 		return ERR_PTR(-ENOMEM);
 	}
-- 
2.29.0