We should prevent user to erasing mtd device with an unaligned offset
or length.
Signed-off-by: Sudip Mukherjee <su...@vectorindia.org>
---
I am not sure if I should add the Signed-off-by of
Dongsheng Yang <yangds.f...@cn.fujitsu.com> . He is the original author
and he should get the credit for that.
drivers/mtd/devices/mtdram.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/drivers/mtd/devices/mtdram.c b/drivers/mtd/devices/mtdram.c
index 8e28508..21b6a05 100644
--- a/drivers/mtd/devices/mtdram.c
+++ b/drivers/mtd/devices/mtdram.c
@@ -32,8 +32,35 @@ 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;
+ uint64_t temp_len, rem;
+
+ /* Start address must align on block boundary */
+ temp_len = ofs;
+ rem = do_div(temp_len, mtd->erasesize);
+ if (rem) {
+ pr_debug("%s: unaligned address\n", __func__);
+ ret = -EINVAL;
+ }
+
+ /* Length must align on block boundary */
+ temp_len = len;
+ rem = do_div(temp_len, mtd->erasesize);
+
+ if (rem) {
+ 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);
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
