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authorYi Liu <yi.l.liu@intel.com>2025-03-05 19:48:42 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-04-20 10:23:21 +0200
commit8c32610aec692ebd4dccd9d29b4ab57bab7a4132 (patch)
tree5992a8f916ff1c674c799356755b740a22cc9dfd
parent4b23c4b991eb90cc7bca42e9f81142feedd4bb56 (diff)
iommufd: Fail replace if device has not been attached
commit 55c85fa7579dc2e3f5399ef5bad67a44257c1a48 upstream. The current implementation of iommufd_device_do_replace() implicitly assumes that the input device has already been attached. However, there is no explicit check to verify this assumption. If another device within the same group has been attached, the replace operation might succeed, but the input device itself may not have been attached yet. As a result, the input device might not be tracked in the igroup->device_list, and its reserved IOVA might not be added. Despite this, the caller might incorrectly assume that the device has been successfully replaced, which could lead to unexpected behavior or errors. To address this issue, add a check to ensure that the input device has been attached before proceeding with the replace operation. This check will help maintain the integrity of the device tracking system and prevent potential issues arising from incorrect assumptions about the device's attachment status. Fixes: e88d4ec154a8 ("iommufd: Add iommufd_device_replace()") Link: https://patch.msgid.link/r/20250306034842.5950-1-yi.l.liu@intel.com Cc: stable@vger.kernel.org Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Yi Liu <yi.l.liu@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/iommu/iommufd/device.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index dfc27de7bab5..3c7800d4ab62 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -354,6 +354,17 @@ iommufd_device_attach_reserved_iova(struct iommufd_device *idev,
/* The device attach/detach/replace helpers for attach_handle */
+/* Check if idev is attached to igroup->hwpt */
+static bool iommufd_device_is_attached(struct iommufd_device *idev)
+{
+ struct iommufd_device *cur;
+
+ list_for_each_entry(cur, &idev->igroup->device_list, group_item)
+ if (cur == idev)
+ return true;
+ return false;
+}
+
static int iommufd_hwpt_attach_device(struct iommufd_hw_pagetable *hwpt,
struct iommufd_device *idev)
{
@@ -593,6 +604,11 @@ iommufd_device_do_replace(struct iommufd_device *idev,
goto err_unlock;
}
+ if (!iommufd_device_is_attached(idev)) {
+ rc = -EINVAL;
+ goto err_unlock;
+ }
+
if (hwpt == igroup->hwpt) {
mutex_unlock(&idev->igroup->lock);
return NULL;