[PATCH] media: lirc: Fix uninitialized variable in ir_lirc_transmit_ir()

[PATCH] media: lirc: Fix uninitialized variable in ir_lirc_transmit_ir()

[Dan Carpenter]

The "txbuf" is uninitialized when we call ir_raw_encode_scancode() so
this failure path would lead to a crash.

Fixes: a74b2bff5945 ("media: lirc: do not pass ERR_PTR to kfree")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
index fae42f120aa4..5efe9cd2309a 100644
--- a/drivers/media/rc/lirc_dev.c
+++ b/drivers/media/rc/lirc_dev.c
@@ -295,7 +295,7 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 		ret = ir_raw_encode_scancode(scan.rc_proto, scan.scancode,
 					     raw, LIRCBUF_SIZE);
 		if (ret < 0)
-			goto out_kfree;
+			goto out_free_raw;
 
 		count = ret;
 
@@ -366,6 +366,7 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
 	return n;
 out_kfree:
 	kfree(txbuf);
+out_free_raw:
 	kfree(raw);
 out_unlock:
 	mutex_unlock(&dev->lock);

Re: [PATCH] media: lirc: Fix uninitialized variable in ir_lirc_transmit_ir()

[Sean Young]

On Wed, Jan 10, 2018 at 12:36:23PM +0300, Dan Carpenter wrote:
> The "txbuf" is uninitialized when we call ir_raw_encode_scancode() so
> this failure path would lead to a crash.

Thanks for reporting this issue, however I'm afraid that the issue has
already been resolved:

https://www.mail-archive.com/linux-media@vger.kernel.org/msg123672.html

and:

https://git.linuxtv.org/media_tree.git/commit/?id=8d25e15d94a2d7b60c28d3a30e4e0e780cab2056

Many thanks,

Sean


> 
> Fixes: a74b2bff5945 ("media: lirc: do not pass ERR_PTR to kfree")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
> index fae42f120aa4..5efe9cd2309a 100644
> --- a/drivers/media/rc/lirc_dev.c
> +++ b/drivers/media/rc/lirc_dev.c
> @@ -295,7 +295,7 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
>  		ret = ir_raw_encode_scancode(scan.rc_proto, scan.scancode,
>  					     raw, LIRCBUF_SIZE);
>  		if (ret < 0)
> -			goto out_kfree;
> +			goto out_free_raw;
>  
>  		count = ret;
>  
> @@ -366,6 +366,7 @@ static ssize_t ir_lirc_transmit_ir(struct file *file, const char __user *buf,
>  	return n;
>  out_kfree:
>  	kfree(txbuf);
> +out_free_raw:
>  	kfree(raw);
>  out_unlock:
>  	mutex_unlock(&dev->lock);