[PATCH] ASoC: SOF: Use struct_size() in kmemdup()

[PATCH] ASoC: SOF: Use struct_size() in kmemdup()

[Gustavo A. R. Silva]

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace code of the following form:

sizeof(*w) + sizeof(struct sof_ipc_window_elem) * w->num_windows

with:

struct_size(w, window, w->num_windows)

Notice that variable size is unnecessary, hence it is removed.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 sound/soc/sof/loader.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/sound/soc/sof/loader.c b/sound/soc/sof/loader.c
index 628fae552442..16b016b76fd8 100644
--- a/sound/soc/sof/loader.c
+++ b/sound/soc/sof/loader.c
@@ -19,15 +19,13 @@ static int get_ext_windows(struct snd_sof_dev *sdev,
 {
 	struct sof_ipc_window *w =
 		container_of(ext_hdr, struct sof_ipc_window, ext_hdr);
-	size_t size;
 
 	if (w->num_windows == 0 || w->num_windows > SOF_IPC_MAX_ELEMS)
 		return -EINVAL;
 
-	size = sizeof(*w) + sizeof(struct sof_ipc_window_elem) * w->num_windows;
-
 	/* keep a local copy of the data */
-	sdev->info_window = kmemdup(w, size, GFP_KERNEL);
+	sdev->info_window = kmemdup(w, struct_size(w, window, w->num_windows),
+				    GFP_KERNEL);
 	if (!sdev->info_window)
 		return -ENOMEM;
 
-- 
2.21.0

Applied "ASoC: SOF: Use struct_size() in kmemdup()" to the asoc tree

[Mark Brown]

The patch

   ASoC: SOF: Use struct_size() in kmemdup()

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.3

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From b11c5b5e573968d69aa9fec7507de7aa8fbf76e6 Mon Sep 17 00:00:00 2001
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Date: Thu, 23 May 2019 10:58:00 -0500
Subject: [PATCH] ASoC: SOF: Use struct_size() in kmemdup()

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace code of the following form:

sizeof(*w) + sizeof(struct sof_ipc_window_elem) * w->num_windows

with:

struct_size(w, window, w->num_windows)

Notice that variable size is unnecessary, hence it is removed.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/sof/loader.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/sound/soc/sof/loader.c b/sound/soc/sof/loader.c
index 628fae552442..16b016b76fd8 100644
--- a/sound/soc/sof/loader.c
+++ b/sound/soc/sof/loader.c
@@ -19,15 +19,13 @@ static int get_ext_windows(struct snd_sof_dev *sdev,
 {
 	struct sof_ipc_window *w =
 		container_of(ext_hdr, struct sof_ipc_window, ext_hdr);
-	size_t size;
 
 	if (w->num_windows == 0 || w->num_windows > SOF_IPC_MAX_ELEMS)
 		return -EINVAL;
 
-	size = sizeof(*w) + sizeof(struct sof_ipc_window_elem) * w->num_windows;
-
 	/* keep a local copy of the data */
-	sdev->info_window = kmemdup(w, size, GFP_KERNEL);
+	sdev->info_window = kmemdup(w, struct_size(w, window, w->num_windows),
+				    GFP_KERNEL);
 	if (!sdev->info_window)
 		return -ENOMEM;
 
-- 
2.20.1