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authorDongsheng Yang <yangds.fnst@cn.fujitsu.com>2015-09-30 04:01:19 +0300
committerBrian Norris <computersforpeace@gmail.com>2015-10-20 04:08:33 +0300
commitab84fce518175aa09ec6e1bb50c2b41dad3e610a (patch)
treec21e33b3f6907e7c3f46bef21d7119e394db0636 /drivers/mtd
parentd3e94f3f2c0f669dfa0d0d51645d5d7d13a9c074 (diff)
downloadlinux-ab84fce518175aa09ec6e1bb50c2b41dad3e610a.tar.xz
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>
Diffstat (limited to 'drivers/mtd')
-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..627a9bc37679 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 (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);