staging: most: Replace all non-returning strlcpy with strscpy

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230523021640.2406585-1-azeemshaikh38@gmail.com

diff --git a/drivers/most/configfs.c b/drivers/most/configfs.c
index 27b0c92..36d8c91 100644 (file)
--- a/drivers/most/configfs.c
+++ b/drivers/most/configfs.c
@@ -204,7 +204,7 @@ static ssize_t mdev_link_device_store(struct config_item *item,
 {
        struct mdev_link *mdev_link = to_mdev_link(item);
 
-       strlcpy(mdev_link->device, page, sizeof(mdev_link->device));
+       strscpy(mdev_link->device, page, sizeof(mdev_link->device));
        strim(mdev_link->device);
        return count;
 }
@@ -219,7 +219,7 @@ static ssize_t mdev_link_channel_store(struct config_item *item,
 {
        struct mdev_link *mdev_link = to_mdev_link(item);
 
-       strlcpy(mdev_link->channel, page, sizeof(mdev_link->channel));
+       strscpy(mdev_link->channel, page, sizeof(mdev_link->channel));
        strim(mdev_link->channel);
        return count;
 }
@@ -234,7 +234,7 @@ static ssize_t mdev_link_comp_store(struct config_item *item,
 {
        struct mdev_link *mdev_link = to_mdev_link(item);
 
-       strlcpy(mdev_link->comp, page, sizeof(mdev_link->comp));
+       strscpy(mdev_link->comp, page, sizeof(mdev_link->comp));
        strim(mdev_link->comp);
        return count;
 }
@@ -250,7 +250,7 @@ static ssize_t mdev_link_comp_params_store(struct config_item *item,
 {
        struct mdev_link *mdev_link = to_mdev_link(item);
 
-       strlcpy(mdev_link->comp_params, page, sizeof(mdev_link->comp_params));
+       strscpy(mdev_link->comp_params, page, sizeof(mdev_link->comp_params));
        strim(mdev_link->comp_params);
        return count;
 }