Change in coreboot[master]: drivers/spi/spi_flash.c: Check input paarameter

[Richard Spiegel (Code Review)]

Richard Spiegel has uploaded this change for review. ( https://review.coreboot.org/27952

Change subject: drivers/spi/spi_flash.c: Check input paarameter
......................................................................

drivers/spi/spi_flash.c: Check input paarameter

In procedure spi_flash_cmd_erase(), parameter "len" is not validated and
could lead to the return of an invalid (not-initialized) value. Validate
the parameter early on.

BUG=b:112253891
TEST=Build and boot grunt.

Change-Id: I0b5129a15c9e0ea45f4dba4ab0729196cb64699b
Signed-off-by: Richard Spiegel 
---
M src/drivers/spi/spi_flash.c
1 file changed, 4 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/52/27952/1

diff --git a/src/drivers/spi/spi_flash.c b/src/drivers/spi/spi_flash.c
index 9cb1085..01ff7b2 100644
--- a/src/drivers/spi/spi_flash.c
+++ b/src/drivers/spi/spi_flash.c
@@ -206,6 +206,10 @@
    	printk(BIOS_WARNING, "SF: Erase offset/length not multiple of erase size\n");
    	return -1;
    }
+	if (len == 0) {
+		printk(BIOS_WARNING, "Erase length cannot be 0\n");
+		return -1;
+	}

cmd[0] = flash->erase_cmd;
    start = offset;