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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>
This commit is contained in:
Dongsheng Yang 2015-09-30 09:01:19 +08:00 committed by Brian Norris
parent d3e94f3f2c
commit ab84fce518
1 changed files with 21 additions and 0 deletions
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21
drivers/mtd/devices/mtdram.c
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@ -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);