[PATCH 1/4] mmc: sdio: Check for CISTPL_VERS_1 buffer size

[Pali RohÃr]

Before parsing CISTPL_VERS_1 structure check that its size is at least two
bytes to prevent buffer overflow.

Signed-off-by: Pali RohÃr <pali@xxxxxxxxxx>
---
 drivers/mmc/core/sdio_cis.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mmc/core/sdio_cis.c b/drivers/mmc/core/sdio_cis.c
index e0655278c5c3..3efaa9534a77 100644
--- a/drivers/mmc/core/sdio_cis.c
+++ b/drivers/mmc/core/sdio_cis.c
@@ -24,10 +24,13 @@ static int cistpl_vers_1(struct mmc_card *card, struct sdio_func *func,
 			 const unsigned char *buf, unsigned size)
 {
 	unsigned i, nr_strings;
 	char **buffer, *string;
 
+	if (size < 2)
+		return 0;
+
 	/* Find all null-terminated (including zero length) strings in
 	   the TPLLV1_INFO field. Trailing garbage is ignored. */
 	buf += 2;
 	size -= 2;
 
-- 
2.20.1