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authorDongsheng Yang <yangds.fnst@cn.fujitsu.com>2015-07-21 16:30:20 +0800
committerBrian Norris <computersforpeace@gmail.com>2015-09-29 15:43:15 -0700
commit7827e3acad2df1c6537e5fe7211d216dabc60399 (patch)
tree7b38b2b3441409c8b882c40462a54608834fabeb
parent8a799590005180b1010912be096c1302e2bd06da (diff)
downloadlinux-7827e3acad2df1c6537e5fe7211d216dabc60399.tar.bz2
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>
-rw-r--r--drivers/mtd/devices/mtdram.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/mtd/devices/mtdram.c b/drivers/mtd/devices/mtdram.c
index 8e285089229c..73fa297d81d2 100644
--- a/drivers/mtd/devices/mtdram.c
+++ b/drivers/mtd/devices/mtdram.c
@@ -32,8 +32,29 @@ MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
// 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 (ofs % mtd->erasesize) {
+ pr_debug("%s: unaligned address\n", __func__);
+ ret = -EINVAL;
+ }
+
+ /* Length must align on block boundary */
+ if (len % mtd->erasesize) {
+ 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);