From b3551ead616318ea155558cdbe7e91495b8d9b33 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Mon, 13 Feb 2023 10:32:21 -0400 Subject: [PATCH] iommufd: Make sure to zero vfio_iommu_type1_info before copying to user Missed a zero initialization here. Most of the struct is filled with a copy_from_user(), however minsz for that copy is smaller than the actual struct by 8 bytes, thus we don't fill the padding. Cc: stable@vger.kernel.org # 6.1+ Fixes: d624d6652a65 ("iommufd: vfio container FD ioctl compatibility") Link: https://lore.kernel.org/r/0-v1-a74499ece799+1a-iommufd_get_info_leak_jgg@nvidia.com Reviewed-by: Kevin Tian Reported-by: syzbot+cb1e0978f6bf46b83a58@syzkaller.appspotmail.com Signed-off-by: Jason Gunthorpe --- drivers/iommu/iommufd/vfio_compat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/iommufd/vfio_compat.c b/drivers/iommu/iommufd/vfio_compat.c index 8e38bb0..514494a 100644 --- a/drivers/iommu/iommufd/vfio_compat.c +++ b/drivers/iommu/iommufd/vfio_compat.c @@ -448,7 +448,7 @@ static int iommufd_vfio_iommu_get_info(struct iommufd_ctx *ictx, }; size_t minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes); struct vfio_info_cap_header __user *last_cap = NULL; - struct vfio_iommu_type1_info info; + struct vfio_iommu_type1_info info = {}; struct iommufd_ioas *ioas; size_t total_cap_size; int rc; -- 2.7.4