UBI: check max_beb_per1024 value in ubi_attach_mtd_dev

max_beb_per1024 shouldn't be negative, and a 0 value will be treated as
the default value. For the upper bound, 768/1024 should be enough.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 8a4eb7c..3700bf7 100644 (file)
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -49,6 +49,9 @@
 /* Maximum number of comma-separated items in the 'mtd=' parameter */
 #define MTD_PARAM_MAX_COUNT 2
 
+/* Maximum value for the number of bad PEBs per 1024 PEBs */
+#define MAX_MTD_UBI_BEB_LIMIT 768
+
 #ifdef CONFIG_MTD_UBI_MODULE
 #define ubi_is_module() 1
 #else
@@ -852,6 +855,12 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
        struct ubi_device *ubi;
        int i, err, ref = 0;
 
+       if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
+               return -EINVAL;
+
+       if (!max_beb_per1024)
+               max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
+
        /*
         * Check if we already have the same MTD device attached.
         *