[PATCH] mtd: mtdram: check offs and len in mtdram->erase

[PATCH] mtd: mtdram: check offs and len in mtdram->erase

[Sudip Mukherjee]

We should prevent user to erasing mtd device with an unaligned offset
or length.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
---

I am not sure if I should add the Signed-off-by of
Dongsheng Yang <yangds.fnst@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

Re: [PATCH] mtd: mtdram: check offs and len in mtdram->erase

[Dongsheng Yang]

On 10/01/2015 12:41 AM, Sudip Mukherjee wrote:
> We should prevent user to erasing mtd device with an unaligned offset
> or length.
>
> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> ---
>
> I am not sure if I should add the Signed-off-by of
> Dongsheng Yang <yangds.fnst@cn.fujitsu.com> . He is the original author
> and he should get the credit for that.

But I had sent a a patch out to fix this problem before your v1.

http://lists.infradead.org/pipermail/linux-mtd/2015-September/062234.html

Yang
>
>   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);
>

Re: [PATCH] mtd: mtdram: check offs and len in mtdram->erase

[Sudip Mukherjee]

On Fri, Oct 02, 2015 at 05:39:02PM +0800, Dongsheng Yang wrote:
> On 10/01/2015 12:41 AM, Sudip Mukherjee wrote:
> >We should prevent user to erasing mtd device with an unaligned offset
> >or length.
> >
> >Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> >---
> >
> >I am not sure if I should add the Signed-off-by of
> >Dongsheng Yang <yangds.fnst@cn.fujitsu.com> . He is the original author
> >and he should get the credit for that.
> 
> But I had sent a a patch out to fix this problem before your v1.
> 
> http://lists.infradead.org/pipermail/linux-mtd/2015-September/062234.html
I didn't know that. I think your v1 was applied.

regards
sudip

Re: [PATCH] mtd: mtdram: check offs and len in mtdram->erase

[Brian Norris]

On Fri, Oct 02, 2015 at 03:31:33PM +0530, Sudip Mukherjee wrote:
> On Fri, Oct 02, 2015 at 05:39:02PM +0800, Dongsheng Yang wrote:
> > On 10/01/2015 12:41 AM, Sudip Mukherjee wrote:
> > >We should prevent user to erasing mtd device with an unaligned offset
> > >or length.
> > >
> > >Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> > >---
> > >
> > >I am not sure if I should add the Signed-off-by of
> > >Dongsheng Yang <yangds.fnst@cn.fujitsu.com> . He is the original author
> > >and he should get the credit for that.
> > 
> > But I had sent a a patch out to fix this problem before your v1.
> > 
> > http://lists.infradead.org/pipermail/linux-mtd/2015-September/062234.html
> I didn't know that. I think your v1 was applied.

Sorry if I left any confusion. Dongsheng's v1 was applied and reverted.
v2 is still under review (and was sent slightly before (?) your v1).
Feel free to comment there.

Brian

Re: [PATCH] mtd: mtdram: check offs and len in mtdram->erase

[Dongsheng Yang]

On 10/03/2015 01:38 AM, Brian Norris wrote:
> On Fri, Oct 02, 2015 at 03:31:33PM +0530, Sudip Mukherjee wrote:
>> On Fri, Oct 02, 2015 at 05:39:02PM +0800, Dongsheng Yang wrote:
>>> On 10/01/2015 12:41 AM, Sudip Mukherjee wrote:
>>>> We should prevent user to erasing mtd device with an unaligned offset
>>>> or length.
>>>>
>>>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
>>>> ---
>>>>
>>>> I am not sure if I should add the Signed-off-by of
>>>> Dongsheng Yang <yangds.fnst@cn.fujitsu.com> . He is the original author
>>>> and he should get the credit for that.
>>>
>>> But I had sent a a patch out to fix this problem before your v1.
>>>
>>> http://lists.infradead.org/pipermail/linux-mtd/2015-September/062234.html
>> I didn't know that. I think your v1 was applied.
>
> Sorry if I left any confusion. Dongsheng's v1 was applied and reverted.
> v2 is still under review (and was sent slightly before (?) your v1).

Yea, sorry I should have mentioned it earlier. But I was and am still
in a vacation, then I did not point it out in time.

Sudip, any comment or test for my patch there is always welcome.

Thanx
Yang
> Feel free to comment there.
>
> Brian
> .
>

Re: [PATCH] mtd: mtdram: check offs and len in mtdram->erase

[Sudip Mukherjee]

On Sat, Oct 03, 2015 at 11:31:04AM +0800, Dongsheng Yang wrote:
> On 10/03/2015 01:38 AM, Brian Norris wrote:
> >On Fri, Oct 02, 2015 at 03:31:33PM +0530, Sudip Mukherjee wrote:
> >>On Fri, Oct 02, 2015 at 05:39:02PM +0800, Dongsheng Yang wrote:
> >>>On 10/01/2015 12:41 AM, Sudip Mukherjee wrote:
> >>>>We should prevent user to erasing mtd device with an unaligned offset
> >>>>or length.
> >>>>
> >>>>Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> >>>>---
> >>>>
> >>>>I am not sure if I should add the Signed-off-by of
> >>>>Dongsheng Yang <yangds.fnst@cn.fujitsu.com> . He is the original author
> >>>>and he should get the credit for that.
> >>>
> >>>But I had sent a a patch out to fix this problem before your v1.
> >>>
> >>>http://lists.infradead.org/pipermail/linux-mtd/2015-September/062234.html
> >>I didn't know that. I think your v1 was applied.
> >
> >Sorry if I left any confusion. Dongsheng's v1 was applied and reverted.
> >v2 is still under review (and was sent slightly before (?) your v1).
> 
> Yea, sorry I should have mentioned it earlier. But I was and am still
> in a vacation, then I did not point it out in time.
> 
> Sudip, any comment or test for my patch there is always welcome.
Sorry, I donot know anything about this driver to comment. My main patch
was to fix the build failure. And since by that time your patch was
reverted so I sent another path with my patch and your patch combined
together.

regards
sudip

[PATCH] mtd: mtdram: check offs and len in mtdram->erase

[Dongsheng Yang]

We should prevent user to erasing mtd device with
an unaligned offset or length.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
---
 drivers/mtd/devices/mtdram.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/mtd/devices/mtdram.c b/drivers/mtd/devices/mtdram.c
index 8e28508..73fa297 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);
-- 
1.8.4.2

Re: [PATCH] mtd: mtdram: check offs and len in mtdram->erase

[Brian Norris]

On Tue, Jul 21, 2015 at 04:30:20PM +0800, Dongsheng Yang wrote:
> We should prevent user to erasing mtd device with
> an unaligned offset or length.
> 
> Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>

Seems reasonable. Pushed to l2-mtd.git.