diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 20c804bdc09c..8fe85f5c7b61 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -217,6 +217,7 @@ struct vfio_device_info {
 	__u32	num_regions;	/* Max region index + 1 */
 	__u32	num_irqs;	/* Max IRQ index + 1 */
 	__u32   cap_offset;	/* Offset within info struct of first cap */
+	__u32   pad;
 };
 #define VFIO_DEVICE_GET_INFO		_IO(VFIO_TYPE, VFIO_BASE + 7)
 
@@ -1304,6 +1305,7 @@ struct vfio_iommu_type1_info {
 #define VFIO_IOMMU_INFO_CAPS	(1 << 1)	/* Info supports caps */
 	__u64	iova_pgsizes;	/* Bitmap of supported page sizes */
 	__u32   cap_offset;	/* Offset within info struct of first cap */
+	__u32   pad;
 };
 
 /*
diff --git a/drivers/iommu/iommufd/vfio_compat.c b/drivers/iommu/iommufd/vfio_compat.c
index fe02517c73cc..6c810bf80f99 100644
--- a/drivers/iommu/iommufd/vfio_compat.c
+++ b/drivers/iommu/iommufd/vfio_compat.c
@@ -483,6 +483,8 @@ static int iommufd_vfio_iommu_get_info(struct iommufd_ctx *ictx,
 			rc = cap_size;
 			goto out_put;
 		}
+		cap_size = ALIGN(cap_size, sizeof(u64));
+
 		if (last_cap && info.argsz >= total_cap_size &&
 		    put_user(total_cap_size, &last_cap->next)) {
 			rc = -EFAULT;
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 20d7b69ea6ff..e2ba2a350f6c 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -920,24 +920,17 @@ static int vfio_pci_ioctl_get_info(struct vfio_pci_core_device *vdev,
 				   struct vfio_device_info __user *arg)
 {
 	unsigned long minsz = offsetofend(struct vfio_device_info, num_irqs);
-	struct vfio_device_info info;
+	struct vfio_device_info info = {};
 	struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
-	unsigned long capsz;
 	int ret;
 
-	/* For backward compatibility, cannot require this */
-	capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
-
 	if (copy_from_user(&info, arg, minsz))
 		return -EFAULT;
 
 	if (info.argsz < minsz)
 		return -EINVAL;
 
-	if (info.argsz >= capsz) {
-		minsz = capsz;
-		info.cap_offset = 0;
-	}
+	minsz = min_t(size_t, info.argsz, sizeof(info));
 
 	info.flags = VFIO_DEVICE_FLAGS_PCI;
 
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index ebe0ad31d0b0..f812c475a626 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -2762,27 +2762,20 @@ static int vfio_iommu_dma_avail_build_caps(struct vfio_iommu *iommu,
 static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu,
 				     unsigned long arg)
 {
-	struct vfio_iommu_type1_info info;
+	struct vfio_iommu_type1_info info = {};
 	unsigned long minsz;
 	struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
-	unsigned long capsz;
 	int ret;
 
 	minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
 
-	/* For backward compatibility, cannot require this */
-	capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
-
 	if (copy_from_user(&info, (void __user *)arg, minsz))
 		return -EFAULT;
 
 	if (info.argsz < minsz)
 		return -EINVAL;
 
-	if (info.argsz >= capsz) {
-		minsz = capsz;
-		info.cap_offset = 0; /* output, no-recopy necessary */
-	}
+	minsz = min_t(size_t, info.argsz, sizeof(info));
 
 	mutex_lock(&iommu->lock);
 	info.flags = VFIO_IOMMU_INFO_PGSIZES;
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index f0ca33b2e1df..2850478301d2 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -1172,6 +1172,9 @@ struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
 	void *buf;
 	struct vfio_info_cap_header *header, *tmp;
 
+	/* Ensure that the next capability struct will be aligned */
+	size = ALIGN(size, sizeof(u64));
+
 	buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
 	if (!buf) {
 		kfree(caps->buf);
@@ -1205,6 +1208,9 @@ void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset)
 	struct vfio_info_cap_header *tmp;
 	void *buf = (void *)caps->buf;
 
+	/* Capability structs should start with proper alignment */
+	WARN_ON(!IS_ALIGNED(offset, sizeof(u64)));
+
 	for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset)
 		tmp->next += offset;
 }
