This makes use of the struct_size() macro to calculate the size of the
struct axi_spi_engine when allocating it.

Suggested-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/spi/spi-axi-spi-engine.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index e801eed820df..9646764b0042 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -12,6 +12,7 @@
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/module.h>
+#include <linux/overflow.h>
 #include <linux/platform_device.h>
 #include <linux/spi/spi.h>
 
@@ -501,15 +502,13 @@ static irqreturn_t spi_engine_irq(int irq, void *devid)
 static int spi_engine_optimize_message(struct spi_message *msg)
 {
 	struct spi_engine_program p_dry, *p;
-	size_t size;
 
 	spi_engine_precompile_message(msg);
 
 	p_dry.length = 0;
 	spi_engine_compile_message(msg, true, &p_dry);
 
-	size = sizeof(*p->instructions) * (p_dry.length + 1);
-	p = kzalloc(sizeof(*p) + size, GFP_KERNEL);
+	p = kzalloc(struct_size(p, instructions, p_dry.length + 1), GFP_KERNEL);
 	if (!p)
 		return -ENOMEM;
 

-- 
2.43.2

On Fri, Mar 01, 2024 at 02:25:20PM -0600, David Lechner wrote:
> This makes use of the struct_size() macro to calculate the size of the
> struct axi_spi_engine when allocating it.
> 
> Suggested-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> Signed-off-by: David Lechner <dlechner@baylibre.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook