Re: [Intel-gfx] [PATCH] drm/i915: prevent integer overflow in query_engine_info()

[Andrzej Hajda]

On 01.09.2022 17:38, Dan Carpenter wrote:

This code uses struct_size() but it stores the result in an int so the
integer overflow checks are not effective.  Record the types as size_t
to prevent the size from being truncated.

Fixes: bf3c50837506 ("drm/i915/query: Use struct_size() helper")
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>

Reviewed-by: Andrzej Hajda <andrzej.ha...@intel.com>

Regards
Andrzej

---
I do not know if the integer overflow can happen.  This is a hardenning
patch just like the conversion to struct_size().

  drivers/gpu/drm/i915/i915_query.c | 5 +++--
  1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_query.c 
b/drivers/gpu/drm/i915/i915_query.c
index 6ec9c9fb7b0d..43a499fbdc8d 100644
--- a/drivers/gpu/drm/i915/i915_query.c
+++ b/drivers/gpu/drm/i915/i915_query.c
@@ -13,7 +13,7 @@
  #include <uapi/drm/i915_drm.h>

static int copy_query_item(void *query_hdr, size_t query_sz,

-                          u32 total_length,
+                          size_t total_length,
                           struct drm_i915_query_item *query_item)
  {
        if (query_item->length == 0)
@@ -135,7 +135,8 @@ query_engine_info(struct drm_i915_private *i915,
        struct drm_i915_engine_info info = { };
        unsigned int num_uabi_engines = 0;
        struct intel_engine_cs *engine;
-       int len, ret;
+       size_t len;
+       int ret;

if (query_item->flags)

                return -EINVAL;