From 7169483ce4570bd2918cb7b1ab04c3e095a22713 Mon Sep 17 00:00:00 2001 From: Kyle Spiers Date: Fri, 27 Apr 2018 15:30:23 -0700 Subject: [PATCH] mfd: rave-sp: Remove VLA As part of the effort to remove VLAs from the kernel[1], this creates constants for the checksum lengths of CCITT and 8B2C and changes crc_calculated to be the maximum size of a checksum. https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Kyle Spiers Reviewed-by: Kees Cook Signed-off-by: Lee Jones --- drivers/mfd/rave-sp.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/mfd/rave-sp.c b/drivers/mfd/rave-sp.c index cb0cc9d509a0..36dcd98977d6 100644 --- a/drivers/mfd/rave-sp.c +++ b/drivers/mfd/rave-sp.c @@ -45,7 +45,9 @@ #define RAVE_SP_DLE 0x10 #define RAVE_SP_MAX_DATA_SIZE 64 -#define RAVE_SP_CHECKSUM_SIZE 2 /* Worst case scenario on RDU2 */ +#define RAVE_SP_CHECKSUM_8B2C 1 +#define RAVE_SP_CHECKSUM_CCITT 2 +#define RAVE_SP_CHECKSUM_SIZE RAVE_SP_CHECKSUM_CCITT /* * We don't store STX, ETX and unescaped bytes, so Rx is only * DATA + CSUM @@ -449,7 +451,12 @@ static void rave_sp_receive_frame(struct rave_sp *sp, const size_t payload_length = length - checksum_length; const u8 *crc_reported = &data[payload_length]; struct device *dev = &sp->serdev->dev; - u8 crc_calculated[checksum_length]; + u8 crc_calculated[RAVE_SP_CHECKSUM_SIZE]; + + if (unlikely(checksum_length > sizeof(crc_calculated))) { + dev_warn(dev, "Checksum too long, dropping\n"); + return; + } print_hex_dump_debug("rave-sp rx: ", DUMP_PREFIX_NONE, 16, 1, data, length, false);