This is supposed to test for integer overflow but it is wrong and
unnecessary.  The size_add()/mul() macros return SIZE_MAX when there is
an integer overflow.  This code saves the SIZE_MAX to a u64 and then
tests if the result is greater than SIZE_MAX which it never will be.
Fortunately, when we try to allocate SIZE_MAX bytes the allocation
will fail.  We even pass __GFP_NOWARN so the allocation fails
harmlessly and quietly.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/gpu/drm/msm/msm_gem_vma.c | 8 +-------
 1 file changed, 1 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c b/drivers/gpu/drm/msm/msm_gem_vma.c
index 71d5238437eb..7968c2dccff0 100644
--- a/drivers/gpu/drm/msm/msm_gem_vma.c
+++ b/drivers/gpu/drm/msm/msm_gem_vma.c
@@ -947,15 +947,9 @@ vm_bind_job_create(struct drm_device *dev, struct drm_file *file,
 		   struct msm_gpu_submitqueue *queue, uint32_t nr_ops)
 {
 	struct msm_vm_bind_job *job;
-	uint64_t sz;
 	int ret;
 
-	sz = struct_size(job, ops, nr_ops);
-
-	if (sz > SIZE_MAX)
-		return ERR_PTR(-ENOMEM);
-
-	job = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN);
+	job = kzalloc(struct_size(job, ops, nr_ops), GFP_KERNEL | __GFP_NOWARN);
 	if (!job)
 		return ERR_PTR(-ENOMEM);
 
-- 
2.51.0

On Thu, 08 Jan 2026 22:57:22 +0300, Dan Carpenter wrote:
> This is supposed to test for integer overflow but it is wrong and
> unnecessary.  The size_add()/mul() macros return SIZE_MAX when there is
> an integer overflow.  This code saves the SIZE_MAX to a u64 and then
> tests if the result is greater than SIZE_MAX which it never will be.
> Fortunately, when we try to allocate SIZE_MAX bytes the allocation
> will fail.  We even pass __GFP_NOWARN so the allocation fails
> harmlessly and quietly.
> 
> [...]

Applied to msm-next, thanks!

[1/1] drm/msm: remove some dead code
      https://gitlab.freedesktop.org/lumag/msm/-/commit/37d2e108de4d

Best regards,
-- 
With best wishes
Dmitry

On Thu, Jan 08, 2026 at 10:57:22PM +0300, Dan Carpenter wrote:
> This is supposed to test for integer overflow but it is wrong and
> unnecessary.  The size_add()/mul() macros return SIZE_MAX when there is
> an integer overflow.  This code saves the SIZE_MAX to a u64 and then
> tests if the result is greater than SIZE_MAX which it never will be.
> Fortunately, when we try to allocate SIZE_MAX bytes the allocation
> will fail.  We even pass __GFP_NOWARN so the allocation fails
> harmlessly and quietly.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
>  drivers/gpu/drm/msm/msm_gem_vma.c | 8 +-------
>  1 file changed, 1 insertions(+), 7 deletions(-)

Fixes: 2e6a8a1fe2b2 ("drm/msm: Add VM_BIND ioctl")

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>


-- 
With best wishes
Dmitry