6.14-stable review patch. If anyone has any objections, please let me know.
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From: Yi Liu yi.l.liu@intel.com
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 --- drivers/iommu/iommufd/device.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
--- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -354,6 +354,17 @@ iommufd_device_attach_reserved_iova(stru
/* 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) { @@ -592,6 +603,11 @@ iommufd_device_do_replace(struct iommufd rc = -EINVAL; goto err_unlock; } + + if (!iommufd_device_is_attached(idev)) { + rc = -EINVAL; + goto err_unlock; + }
if (hwpt == igroup->hwpt) { mutex_unlock(&idev->igroup->lock);