nouveau/u_memcpya: fix NULL vs error pointer bug

Dan Carpenter · dakr · commit c5f9362307c6 · 2023-09-20T00:20:08.000+02:00
The u_memcpya() function is supposed to return error pointers on error. Returning NULL will lead to an Oops. Fixes: e3885f7 ("nouveau/u_memcpya: use vmemdup_user") Reviewed-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Danilo Krummrich <dakr@redhat.com> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Danilo Krummrich <dakr@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/10fd258b-466f-4c5b-9d48-fe61a3f21424@moroto.mountain
diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -193,7 +193,7 @@ u_memcpya(uint64_t user, unsigned int nmemb, unsigned int size)
 	size_t bytes;
 
 	if (unlikely(check_mul_overflow(nmemb, size, &bytes)))
-		return NULL;
+		return ERR_PTR(-EOVERFLOW);
 	return vmemdup_user(userptr, bytes);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -193,7 +193,7 @@ u_memcpya(uint64_t user, unsigned int nmemb, unsigned int size)`
`193`	`193`	`size_t bytes;`
`194`	`194`
`195`	`195`	`if (unlikely(check_mul_overflow(nmemb, size, &bytes)))`
`196`		`- return NULL;`
	`196`	`+ return ERR_PTR(-EOVERFLOW);`
`197`	`197`	`return vmemdup_user(userptr, bytes);`
`198`	`198`	`}`
`199`	`199`