Re: [PATCH 2/3] iommufd: Add check on user response code
From: Baolu Lu
Date: Thu Jul 11 2024 - 22:57:15 EST
On 7/12/24 7:39 AM, Jason Gunthorpe wrote:
On Wed, Jul 10, 2024 at 04:33:40PM +0800, Lu Baolu wrote:
The response code from user space is only allowed to be SUCCESS or
INVALID. All other values are treated by the device as a response
code of Response Failure according to PCI spec, section 10.4.2.1.
This response disables the Page Request Interface for the Function.
Add a check in iommufd_fault_fops_write() to avoid invalid response
code.
Fixes: 07838f7fd529 ("iommufd: Add iommufd fault object")
Signed-off-by: Lu Baolu<baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/iommufd/fault.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c
index 54d6cd20a673..044b9b97da31 100644
--- a/drivers/iommu/iommufd/fault.c
+++ b/drivers/iommu/iommufd/fault.c
@@ -305,6 +305,12 @@ static ssize_t iommufd_fault_fops_write(struct file *filep, const char __user *b
if (rc)
break;
+ if (response.code != IOMMUFD_PAGE_RESP_SUCCESS &&
+ response.code != IOMMUFD_PAGE_RESP_INVALID) {
+ rc = -EINVAL;
+ break;
+ }
I added this:
static_assert(IOMMUFD_PAGE_RESP_SUCCESS ==
IOMMU_PAGE_RESP_SUCCESS);
static_assert(IOMMUFD_PAGE_RESP_INVALID ==
IOMMU_PAGE_RESP_INVALID);
Above change cause below build warning:
drivers/iommu/iommufd/fault.c: In function ‘iommufd_fault_fops_write’:
drivers/iommu/iommufd/fault.c:308:57: warning: comparison between ‘enum
iommufd_page_response_code’ and ‘enum iommu_page_response_code’
[-Wenum-compare]
308 | static_assert(IOMMUFD_PAGE_RESP_SUCCESS ==
| ^~
./include/linux/build_bug.h:78:56: note: in definition of macro
‘__static_assert’
78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
| ^~~~
drivers/iommu/iommufd/fault.c:308:17: note: in expansion of macro
‘static_assert’
308 | static_assert(IOMMUFD_PAGE_RESP_SUCCESS ==
| ^~~~~~~~~~~~~
drivers/iommu/iommufd/fault.c:310:57: warning: comparison between ‘enum
iommufd_page_response_code’ and ‘enum iommu_page_response_code’
[-Wenum-compare]
310 | static_assert(IOMMUFD_PAGE_RESP_INVALID ==
| ^~
./include/linux/build_bug.h:78:56: note: in definition of macro
‘__static_assert’
78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
| ^~~~
drivers/iommu/iommufd/fault.c:310:17: note: in expansion of macro
‘static_assert’
310 | static_assert(IOMMUFD_PAGE_RESP_INVALID ==
| ^~~~~~~~~~~~~
Perhaps convert them to 'int' before compare?
diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c
index 29f522819759..a643d5c7c535 100644
--- a/drivers/iommu/iommufd/fault.c
+++ b/drivers/iommu/iommufd/fault.c
@@ -305,10 +305,10 @@ static ssize_t iommufd_fault_fops_write(struct
file *filep, const char __user *b
if (rc)
break;
- static_assert(IOMMUFD_PAGE_RESP_SUCCESS ==
- IOMMU_PAGE_RESP_SUCCESS);
- static_assert(IOMMUFD_PAGE_RESP_INVALID ==
- IOMMU_PAGE_RESP_INVALID);
+ static_assert((int)IOMMUFD_PAGE_RESP_SUCCESS ==
+ (int)IOMMU_PAGE_RESP_SUCCESS);
+ static_assert((int)IOMMUFD_PAGE_RESP_INVALID ==
+ (int)IOMMU_PAGE_RESP_INVALID);
if (response.code != IOMMUFD_PAGE_RESP_SUCCESS &&
response.code != IOMMUFD_PAGE_RESP_INVALID) {
rc = -EINVAL;
Thanks,
baolu