2022-03-02 23:35:58

by Nguyen Dinh Phi

Subject: [PATCH RESEND] samples/kobject: Use sysfs_emit instead of snprintf

Convert sprintf() to sysfs_emit() in order to check buffer overrun on sysfs
outputs.

Signed-off-by: Nguyen Dinh Phi <[email protected]>
---
samples/kobject/kobject-example.c | 4 ++--
samples/kobject/kset-example.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/samples/kobject/kobject-example.c b/samples/kobject/kobject-example.c
index 9e383fdbaa00..96678ed73216 100644
--- a/samples/kobject/kobject-example.c
+++ b/samples/kobject/kobject-example.c
@@ -28,7 +28,7 @@ static int bar;
static ssize_t foo_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
- return sprintf(buf, "%d\n", foo);
+ return sysfs_emit(buf, "%d\n", foo);
}

static ssize_t foo_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -60,7 +60,7 @@ static ssize_t b_show(struct kobject *kobj, struct kobj_attribute *attr,
var = baz;
else
var = bar;
- return sprintf(buf, "%d\n", var);
+ return sysfs_emit(buf, "%d\n", var);
}

static ssize_t b_store(struct kobject *kobj, struct kobj_attribute *attr,
diff --git a/samples/kobject/kset-example.c b/samples/kobject/kset-example.c
index c8010f126808..52f1acabd479 100644
--- a/samples/kobject/kset-example.c
+++ b/samples/kobject/kset-example.c
@@ -112,7 +112,7 @@ static void foo_release(struct kobject *kobj)
static ssize_t foo_show(struct foo_obj *foo_obj, struct foo_attribute *attr,
char *buf)
{
- return sprintf(buf, "%d\n", foo_obj->foo);
+ return sysfs_emit(buf, "%d\n", foo_obj->foo);
}

static ssize_t foo_store(struct foo_obj *foo_obj, struct foo_attribute *attr,
@@ -144,7 +144,7 @@ static ssize_t b_show(struct foo_obj *foo_obj, struct foo_attribute *attr,
var = foo_obj->baz;
else
var = foo_obj->bar;
- return sprintf(buf, "%d\n", var);
+ return sysfs_emit(buf, "%d\n", var);
}

static ssize_t b_store(struct foo_obj *foo_obj, struct foo_attribute *attr,
--
2.25.1

2022-03-03 00:30:39

by Greg Kroah-Hartman

Subject: Re: [PATCH RESEND] samples/kobject: Use sysfs_emit instead of snprintf

On Wed, Mar 02, 2022 at 08:07:59PM +0800, Nguyen Dinh Phi wrote:
> Convert sprintf() to sysfs_emit() in order to check buffer overrun on sysfs
> outputs.

There are no such buffer overruns on these sysfs files.

>
> Signed-off-by: Nguyen Dinh Phi <[email protected]>
> ---
> samples/kobject/kobject-example.c | 4 ++--
> samples/kobject/kset-example.c | 4 ++--
> 2 files changed, 4 insertions(+), 4 deletions(-)

Why is this a resend? What happened to the first version?

thanks,

greg k-h