[PATCH] doubletalk: probe failure causes OOPS

[PATCH] doubletalk: probe failure causes OOPS

[Alan Cox]

The code bothers to probe for the device, but on failing to find it proceeds
to try and release a NULL resource, thereby ruining it's prior good
behaviour

Resolves-Bug: https://bugzilla.kernel.org/show_bug.cgi?id=88581
Signed-off-by: Alan Cox <alan@linux.intel.com>
---
 drivers/staging/speakup/speakup_dtlk.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/speakup/speakup_dtlk.c b/drivers/staging/speakup/speakup_dtlk.c
index d7d5152..ffd85e1 100644
--- a/drivers/staging/speakup/speakup_dtlk.c
+++ b/drivers/staging/speakup/speakup_dtlk.c
@@ -325,7 +325,7 @@ static struct synth_settings *synth_interrogate(struct spk_synth *synth)
 
 static int synth_probe(struct spk_synth *synth)
 {
-		unsigned int port_val = 0;
+	unsigned int port_val = 0;
 	int i = 0;
 	struct synth_settings *sp;
 
@@ -361,7 +361,8 @@ static int synth_probe(struct spk_synth *synth)
 	port_val &= 0xfbff;
 	if (port_val != 0x107f) {
 		pr_info("DoubleTalk PC: not found\n");
-		synth_release_region(synth_lpc, SYNTH_IO_EXTENT);
+		if (synth_lpc)
+			synth_release_region(synth_lpc, SYNTH_IO_EXTENT);
 		return -ENODEV;
 	}
 	while (inw_p(synth_lpc) != 0x147f)
@@ -369,7 +370,7 @@ static int synth_probe(struct spk_synth *synth)
 	sp = synth_interrogate(synth);
 	pr_info("%s: %03x-%03x, ROM ver %s, s/n %u, driver: %s\n",
 		synth->long_name, synth_lpc, synth_lpc+SYNTH_IO_EXTENT - 1,
-	 sp->rom_version, sp->serial_number, synth->version);
+		sp->rom_version, sp->serial_number, synth->version);
 	synth->alive = 1;
 	return 0;
 }

Re: [PATCH] doubletalk: probe failure causes OOPS

[Jiri Kosina]

On Mon, 15 Dec 2014, Alan Cox wrote:

> The code bothers to probe for the device, but on failing to find it proceeds
> to try and release a NULL resource, thereby ruining it's prior good
> behaviour
> 
> Resolves-Bug: https://bugzilla.kernel.org/show_bug.cgi?id=88581
> Signed-off-by: Alan Cox <alan@linux.intel.com>

Doesn't seem to be in linux-next as of today, so I am picking it up.

> ---
>  drivers/staging/speakup/speakup_dtlk.c |    7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/staging/speakup/speakup_dtlk.c b/drivers/staging/speakup/speakup_dtlk.c
> index d7d5152..ffd85e1 100644
> --- a/drivers/staging/speakup/speakup_dtlk.c
> +++ b/drivers/staging/speakup/speakup_dtlk.c
> @@ -325,7 +325,7 @@ static struct synth_settings *synth_interrogate(struct spk_synth *synth)
>  
>  static int synth_probe(struct spk_synth *synth)
>  {
> -		unsigned int port_val = 0;
> +	unsigned int port_val = 0;
>  	int i = 0;
>  	struct synth_settings *sp;
>  
> @@ -361,7 +361,8 @@ static int synth_probe(struct spk_synth *synth)
>  	port_val &= 0xfbff;
>  	if (port_val != 0x107f) {
>  		pr_info("DoubleTalk PC: not found\n");
> -		synth_release_region(synth_lpc, SYNTH_IO_EXTENT);
> +		if (synth_lpc)
> +			synth_release_region(synth_lpc, SYNTH_IO_EXTENT);
>  		return -ENODEV;
>  	}
>  	while (inw_p(synth_lpc) != 0x147f)
> @@ -369,7 +370,7 @@ static int synth_probe(struct spk_synth *synth)
>  	sp = synth_interrogate(synth);
>  	pr_info("%s: %03x-%03x, ROM ver %s, s/n %u, driver: %s\n",
>  		synth->long_name, synth_lpc, synth_lpc+SYNTH_IO_EXTENT - 1,
> -	 sp->rom_version, sp->serial_number, synth->version);
> +		sp->rom_version, sp->serial_number, synth->version);
>  	synth->alive = 1;
>  	return 0;
>  }
> 

-- 
Jiri Kosina
SUSE Labs