[alsa-devel] [PATCH 1/2] hda - fix ELD memory leak

[Takashi Iwai]

At Tue, 15 Nov 2011 22:41:16 +0800,
Wu Fengguang wrote:
> 
> On Tue, Nov 15, 2011 at 10:35:41PM +0800, Takashi Iwai wrote:
> > At Tue, 15 Nov 2011 22:31:55 +0800,
> > Wu Fengguang wrote:
> > > 
> > > memset(eld) clears eld->proc_entry which will leak the struct
> > > snd_info_entry when unloading the module.
> > > 
> > > Fix it by
> > > - remove memset(eld)
> > > - set eld->eld_valid to true _after_ all eld fields have been filled
> > > - don't access the other eld fields when (eld->eld_valid == false)
> > > 
> > > Signed-off-by: Wu Fengguang <fengguang.wu at intel.com>
> > 
> > This should be send to stable kernel, too, right?
> > It appears in 3.1, at least.
> 
> Yeah. Good point!  I'll resend it when everything goes fine.

Ah, no, you don't need to resend.  I'd just need to put Cc to stable
in the patch commit log.  Then Greg will pick it up automatically
when the tree is merged to the upstream.

But of course I need to know beforehand whether the patch is intended
to be sent to stable or not.


Takashi

> 
> Thanks,
> Fengguang
> 
> > > ---
> > >  sound/pci/hda/hda_eld.c    |    5 +----
> > >  sound/pci/hda/patch_hdmi.c |   11 +++++------
> > >  2 files changed, 6 insertions(+), 10 deletions(-)
> > > 
> > > --- linux.orig/sound/pci/hda/hda_eld.c	2011-11-15 21:02:25.000000000 +0800
> > > +++ linux/sound/pci/hda/hda_eld.c	2011-11-15 21:13:46.000000000 +0800
> > > @@ -297,10 +297,10 @@ static int hdmi_update_eld(struct hdmi_e
> > >  					buf + ELD_FIXED_BYTES + mnl + 3 * i);
> > >  	}
> > >  
> > > +	e->eld_valid = true;
> > >  	return 0;
> > >  
> > >  out_fail:
> > > -	e->eld_ver = 0;
> > >  	return -EINVAL;
> > >  }
> > >  
> > > @@ -323,9 +323,6 @@ int snd_hdmi_get_eld(struct hdmi_eld *el
> > >  	 * ELD is valid, actual eld_size is assigned in hdmi_update_eld()
> > >  	 */
> > >  
> > > -	if (!eld->eld_valid)
> > > -		return -ENOENT;
> > > -
> > >  	size = snd_hdmi_get_eld_size(codec, nid);
> > >  	if (size == 0) {
> > >  		/* wfg: workaround for ASUS P5E-VM HDMI board */
> > > --- linux.orig/sound/pci/hda/patch_hdmi.c	2011-11-15 21:02:25.000000000 +0800
> > > +++ linux/sound/pci/hda/patch_hdmi.c	2011-11-15 21:13:42.000000000 +0800
> > > @@ -980,20 +980,19 @@ static void hdmi_present_sense(struct hd
> > >  	 * the unsolicited response to avoid custom WARs.
> > >  	 */
> > >  	int present = snd_hda_pin_sense(codec, pin_nid);
> > > +	bool eld_valid = false;
> > >  
> > > -	memset(eld, 0, sizeof(*eld));
> > > +	eld->eld_valid = false;
> > >  
> > >  	eld->monitor_present	= !!(present & AC_PINSENSE_PRESENCE);
> > >  	if (eld->monitor_present)
> > > -		eld->eld_valid	= !!(present & AC_PINSENSE_ELDV);
> > > -	else
> > > -		eld->eld_valid	= 0;
> > > +		eld_valid	= !!(present & AC_PINSENSE_ELDV);
> > >  
> > >  	printk(KERN_INFO
> > >  		"HDMI status: Codec=%d Pin=%d Presence_Detect=%d ELD_Valid=%d\n",
> > > -		codec->addr, pin_nid, eld->monitor_present, eld->eld_valid);
> > > +		codec->addr, pin_nid, eld->monitor_present, eld_valid);
> > >  
> > > -	if (eld->eld_valid)
> > > +	if (eld_valid)
> > >  		if (!snd_hdmi_get_eld(eld, codec, pin_nid))
> > >  			snd_hdmi_show_eld(eld);
> > >  
> > > 
>