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Message-ID: <20170317022939.5511-1-chenwy-fnst@cn.fujitsu.com>
Date: Fri, 17 Mar 2017 10:29:39 +0800
From: chenwy <chenwy-fnst@...fujitsu.com>
To: <linux-mtd@...ts.infradead.org>
CC: <fnstml-fjl@...fujitsu.com>, <linux-kernel@...r.kernel.org>,
chenwy <chenwy-fnst@...fujitsu.com>
Subject: [PATCH v2] mtdram: check offs and len where appropriate
We should prevent user to operating mtd device with
an illegal offset or length.
Signed-off-by: Chen Wenyong <chenwy-fnst@...fujitsu.com>
---
drivers/mtd/devices/mtdram.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/mtd/devices/mtdram.c b/drivers/mtd/devices/mtdram.c
index cbd8547..83e1603 100644
--- a/drivers/mtd/devices/mtdram.c
+++ b/drivers/mtd/devices/mtdram.c
@@ -58,6 +58,10 @@ static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
{
if (check_offs_len(mtd, instr->addr, instr->len))
return -EINVAL;
+ if (mtd->size < (instr->len + instr->addr) || instr->addr < 0
+ || instr->len < 0)
+ return -EINVAL;
+
memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);
@@ -67,6 +71,9 @@ static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, void **virt, resource_size_t *phys)
{
+ if (mtd->size < (len + from) || from < 0 || len < 0)
+ return -EINVAL;
+
*virt = mtd->priv + from;
*retlen = len;
return 0;
@@ -74,6 +81,9 @@ static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
+ if (mtd->size < (len + from) || from < 0 || len < 0)
+ return -EINVAL;
+
return 0;
}
@@ -93,6 +103,9 @@ static unsigned long ram_get_unmapped_area(struct mtd_info *mtd,
static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
+ if (mtd->size < (len + from) || from < 0 || len < 0)
+ return -EINVAL;
+
memcpy(buf, mtd->priv + from, len);
*retlen = len;
return 0;
@@ -101,6 +114,9 @@ static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
+ if (mtd->size < (len + to) || to < 0 || len < 0)
+ return -EINVAL;
+
memcpy((char *)mtd->priv + to, buf, len);
*retlen = len;
return 0;
--
2.9.3
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