[PATCH -next 1/3] powerpc/rtas: Replaced simple_strtoull() with kstrtoull()

[PATCH -next 1/3] powerpc/rtas: Replaced simple_strtoull() with kstrtoull()

[Chen Huang]

The simple_strtoull() function is deprecated in some situation, since
it does not check for the range overflow, use kstrtoull() instead.

Signed-off-by: Chen Huang <chenhuang5@huawei.com>
---
 arch/powerpc/kernel/rtas-proc.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/rtas-proc.c b/arch/powerpc/kernel/rtas-proc.c
index 6857a5b0a1c3..117886782ebd 100644
--- a/arch/powerpc/kernel/rtas-proc.c
+++ b/arch/powerpc/kernel/rtas-proc.c
@@ -259,7 +259,6 @@ __initcall(proc_rtas_init);
 static int parse_number(const char __user *p, size_t count, u64 *val)
 {
 	char buf[40];
-	char *end;
 
 	if (count > 39)
 		return -EINVAL;
@@ -269,11 +268,7 @@ static int parse_number(const char __user *p, size_t count, u64 *val)
 
 	buf[count] = 0;
 
-	*val = simple_strtoull(buf, &end, 10);
-	if (*end && *end != '\n')
-		return -EINVAL;
-
-	return 0;
+	return kstrtoull(buf, 10, val);
 }
 
 /* ****************************************************************** */
-- 
2.25.1

[PATCH -next 2/3] xen: balloon: Replaced simple_strtoull() with kstrtoull()

[Chen Huang]

The simple_strtoull() function is deprecated in some situation, since
it does not check for the range overflow, use kstrtoull() instead.

Signed-off-by: Chen Huang <chenhuang5@huawei.com>
---
 drivers/xen/xen-balloon.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c
index a8d24433c8e9..1fba838963d2 100644
--- a/drivers/xen/xen-balloon.c
+++ b/drivers/xen/xen-balloon.c
@@ -163,13 +163,16 @@ static ssize_t store_target_kb(struct device *dev,
 			       const char *buf,
 			       size_t count)
 {
-	char *endchar;
+	ssize_t ret;
 	unsigned long long target_bytes;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	target_bytes = simple_strtoull(buf, &endchar, 0) * 1024;
+	ret = kstrtoull(buf, 0, &target_bytes);
+	if (ret)
+		return ret;
+	target_bytes *= 1024;
 
 	balloon_set_new_target(target_bytes >> PAGE_SHIFT);
 
-- 
2.25.1

[PATCH -next 3/3] ocfs2: Replaced simple_strtoull() with kstrtoull()

[Chen Huang]

The simple_strtoull() function is deprecated in some situation since
it does not check for the range overflow, use kstrtoull() instead.

Signed-off-by: Chen Huang <chenhuang5@huawei.com>
---
 fs/ocfs2/cluster/heartbeat.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c
index 1169c8dc9106..f89ffcbd585f 100644
--- a/fs/ocfs2/cluster/heartbeat.c
+++ b/fs/ocfs2/cluster/heartbeat.c
@@ -1596,12 +1596,13 @@ static ssize_t o2hb_region_start_block_store(struct config_item *item,
 	struct o2hb_region *reg = to_o2hb_region(item);
 	unsigned long long tmp;
 	char *p = (char *)page;
+	ssize_t ret;
 
 	if (reg->hr_bdev)
 		return -EINVAL;
 
-	tmp = simple_strtoull(p, &p, 0);
-	if (!p || (*p && (*p != '\n')))
+	ret = kstrtoull(p, 0, &tmp);
+	if (ret)
 		return -EINVAL;
 
 	reg->hr_start_block = tmp;
-- 
2.25.1

RE: [PATCH -next 2/3] xen: balloon: Replaced simple_strtoull() with kstrtoull()

[David Laight]

From: Chen Huang
> Sent: 26 May 2021 10:20
> 
> The simple_strtoull() function is deprecated in some situation, since
> it does not check for the range overflow, use kstrtoull() instead.
> 
...
> -	target_bytes = simple_strtoull(buf, &endchar, 0) * 1024;
> +	ret = kstrtoull(buf, 0, &target_bytes);
> +	if (ret)
> +		return ret;
> +	target_bytes *= 1024;

I'd have thought it was more important to check *endchar
than overflow.
If you are worried about overflow you need a range check
before the multiply.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: [PATCH -next 2/3] xen: balloon: Replaced simple_strtoull() with kstrtoull()

[Dan Carpenter]

On Thu, May 27, 2021 at 02:10:21PM +0000, David Laight wrote:
> From: Chen Huang
> > Sent: 26 May 2021 10:20
> > 
> > The simple_strtoull() function is deprecated in some situation, since
> > it does not check for the range overflow, use kstrtoull() instead.
> > 
> ...
> > -	target_bytes = simple_strtoull(buf, &endchar, 0) * 1024;
> > +	ret = kstrtoull(buf, 0, &target_bytes);
> > +	if (ret)
> > +		return ret;
> > +	target_bytes *= 1024;
> 
> I'd have thought it was more important to check *endchar
> than overflow.

That's one of the differences between simple_strtoull() and kstrtoull().
The simple_strtoull() will accept a string like "123ABC", but kstrtoull()
will only accept NUL terminated numbers or a newline followed by a NUL
terminator.  Which is fine in this context because users will be doing
"echo 1234 > /sys/foo".

> If you are worried about overflow you need a range check
> before the multiply.

This is probably a case where if the users cause an integer overflow
then they get what they deserve.

regards,
dan carpenter