mtd: mtdram: check offs and len in mtdram->erase
We should prevent user to erasing mtd device with
an unaligned offset or length.
Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/devices/mtdram.c b/drivers/mtd/devices/mtdram.c
index 8e28508..627a9bc 100644
--- a/drivers/mtd/devices/mtdram.c
+++ b/drivers/mtd/devices/mtdram.c
@@ -32,8 +32,29 @@
// We could store these in the mtd structure, but we only support 1 device..
static struct mtd_info *mtd_info;
+static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+ int ret = 0;
+
+ /* Start address must align on block boundary */
+ if (mtd_mod_by_eb(ofs, mtd)) {
+ pr_debug("%s: unaligned address\n", __func__);
+ ret = -EINVAL;
+ }
+
+ /* Length must align on block boundary */
+ if (mtd_mod_by_eb(len, mtd)) {
+ pr_debug("%s: length not block aligned\n", __func__);
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
{
+ if (check_offs_len(mtd, instr->addr, instr->len))
+ return -EINVAL;
memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);