[PATCH 5.5 45/80] bus: moxtet: fix potential stack buffer overflow

[Greg Kroah-Hartman]

From: Marek BehÃn <marek.behun@xxxxxx>

commit 3bf3c9744694803bd2d6f0ee70a6369b980530fd upstream.

The input_read function declares the size of the hex array relative to
sizeof(buf), but buf is a pointer argument of the function. The hex
array is meant to contain hexadecimal representation of the bin array.

Link: https://lore.kernel.org/r/20200215142130.22743-1-marek.behun@xxxxxx
Fixes: 5bc7f990cd98 ("bus: Add support for Moxtet bus")
Signed-off-by: Marek BehÃn <marek.behun@xxxxxx>
Reported-by: sohu0106 <sohu0106@xxxxxxx>
Signed-off-by: Olof Johansson <olof@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/bus/moxtet.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/bus/moxtet.c
+++ b/drivers/bus/moxtet.c
@@ -466,7 +466,7 @@ static ssize_t input_read(struct file *f
 {
 	struct moxtet *moxtet = file->private_data;
 	u8 bin[TURRIS_MOX_MAX_MODULES];
-	u8 hex[sizeof(buf) * 2 + 1];
+	u8 hex[sizeof(bin) * 2 + 1];
 	int ret, n;
 
 	ret = moxtet_spi_read(moxtet, bin);