Re: [PATCH v4.19.y] drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Fri, Aug 04, 2023 at 12:22:09PM +0200, Greg Kroah-Hartman wrote:
> On Tue, Aug 01, 2023 at 02:30:44PM -0700, Brennan Lamoreaux wrote:
> > From: Joe Perches <joe@perches.com>
> > 
> > commit aa838896d87af561a33ecefea1caa4c15a68bc47 upstream
> > 
> > Convert the various sprintf fmaily calls in sysfs device show functions
> > to sysfs_emit and sysfs_emit_at for PAGE_SIZE buffer safety.
> > 
> > Done with:
> > 
> > $ spatch -sp-file sysfs_emit_dev.cocci --in-place --max-width=80 .
> > 
> > And cocci script:
> > 
> > $ cat sysfs_emit_dev.cocci
> > @@
> > identifier d_show;
> > identifier dev, attr, buf;
> > @@
> > 
> > ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> > {
> > 	<...
> > 	return
> > -	sprintf(buf,
> > +	sysfs_emit(buf,
> > 	...);
> > 	...>
> > }
> > 
> > @@
> > identifier d_show;
> > identifier dev, attr, buf;
> > @@
> > 
> > ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> > {
> > 	<...
> > 	return
> > -	snprintf(buf, PAGE_SIZE,
> > +	sysfs_emit(buf,
> > 	...);
> > 	...>
> > }
> > 
> > @@
> > identifier d_show;
> > identifier dev, attr, buf;
> > @@
> > 
> > ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> > {
> > 	<...
> > 	return
> > -	scnprintf(buf, PAGE_SIZE,
> > +	sysfs_emit(buf,
> > 	...);
> > 	...>
> > }
> > 
> > @@
> > identifier d_show;
> > identifier dev, attr, buf;
> > expression chr;
> > @@
> > 
> > ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> > {
> > 	<...
> > 	return
> > -	strcpy(buf, chr);
> > +	sysfs_emit(buf, chr);
> > 	...>
> > }
> > 
> > @@
> > identifier d_show;
> > identifier dev, attr, buf;
> > identifier len;
> > @@
> > 
> > ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> > {
> > 	<...
> > 	len =
> > -	sprintf(buf,
> > +	sysfs_emit(buf,
> > 	...);
> > 	...>
> > 	return len;
> > }
> > 
> > @@
> > identifier d_show;
> > identifier dev, attr, buf;
> > identifier len;
> > @@
> > 
> > ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> > {
> > 	<...
> > 	len =
> > -	snprintf(buf, PAGE_SIZE,
> > +	sysfs_emit(buf,
> > 	...);
> > 	...>
> > 	return len;
> > }
> > 
> > @@
> > identifier d_show;
> > identifier dev, attr, buf;
> > identifier len;
> > @@
> > 
> > ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> > {
> > 	<...
> > 	len =
> > -	scnprintf(buf, PAGE_SIZE,
> > +	sysfs_emit(buf,
> > 	...);
> > 	...>
> > 	return len;
> > }
> > 
> > @@
> > identifier d_show;
> > identifier dev, attr, buf;
> > identifier len;
> > @@
> > 
> > ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> > {
> > 	<...
> > -	len += scnprintf(buf + len, PAGE_SIZE - len,
> > +	len += sysfs_emit_at(buf, len,
> > 	...);
> > 	...>
> > 	return len;
> > }
> > 
> > @@
> > identifier d_show;
> > identifier dev, attr, buf;
> > expression chr;
> > @@
> > 
> > ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
> > {
> > 	...
> > -	strcpy(buf, chr);
> > -	return strlen(buf);
> > +	return sysfs_emit(buf, chr);
> > }
> > 
> > Signed-off-by: Joe Perches <joe@perches.com>
> > Link: https://lore.kernel.org/r/3d033c33056d88bbe34d4ddb62afd05ee166ab9a.1600285923.git.joe@perches.com
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > [ Brennan : Regenerated for 4.19 to fix CVE-2022-20166 ]
> > Signed-off-by: Brennan Lamoreaux <blamoreaux@vmware.com>
> 
> Thanks, now queued up.

Nope, now dropped, this didn't even build.  How did you test this thing?

{sigh}

greg k-h