[PATCH] android/client/if-bt.c: Fix memory leak while using realloc()

[PATCH] android/client/if-bt.c: Fix memory leak while using realloc()

[Atul Rai]

While reallocating space to store additional "remote device set" using
realloc, if realloc() fails, the original block is left untouched but
reference to that block is lost as NULL is assigned to remote_devices.
The original block needs to be freed before return.

Signed-off-by: Atul Rai <a.rai@samsung.com>
---
 android/client/if-bt.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/android/client/if-bt.c b/android/client/if-bt.c
index 4723024..4f0c2e9 100644
--- a/android/client/if-bt.c
+++ b/android/client/if-bt.c
@@ -94,6 +94,7 @@ static int remote_devices_capacity = 0;
 void add_remote_device(const bt_bdaddr_t *addr)
 {
 	int i;
+	bt_bdaddr_t *tmp = NULL;
 
 	if (remote_devices == NULL) {
 		remote_devices = malloc(4 * sizeof(bt_bdaddr_t));
@@ -119,9 +120,17 @@ void add_remote_device(const bt_bdaddr_t *addr)
 	/* Realloc space if needed */
 	if (remote_devices_cnt >= remote_devices_capacity) {
 		remote_devices_capacity *= 2;
+		/*
+		 * Save reference to previously allocated memory block so that
+		 * it can be freed in case realloc fails.
+		 */
+		tmp = remote_devices;
+
 		remote_devices = realloc(remote_devices, sizeof(bt_bdaddr_t) *
 						remote_devices_capacity);
 		if (remote_devices == NULL) {
+			if (NULL != tmp)
+				free(tmp);
 			remote_devices_capacity = 0;
 			remote_devices_cnt = 0;
 			return;
-- 
2.1.4

Re: [PATCH] android/client/if-bt.c: Fix memory leak while using realloc()

[Atul Rai]

ping

> ------- Original Message -------
> Sender : Atul Kumar Rai<a.rai@samsung.com> Lead Engineer (1)/SRI-Delhi-SWC Group/Samsung Electronics
> Date : Jun 23, 2015 13:38 (GMT+05:30)
> Title : [PATCH] android/client/if-bt.c: Fix memory leak while using realloc()
> 
> While reallocating space to store additional "remote device set" using
> realloc, if realloc() fails, the original block is left untouched but
> reference to that block is lost as NULL is assigned to remote_devices.
> The original block needs to be freed before return.
> 
> Signed-off-by: Atul Rai <a.rai@samsung.com>
> ---
>  android/client/if-bt.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/android/client/if-bt.c b/android/client/if-bt.c
> index 4723024..4f0c2e9 100644
> --- a/android/client/if-bt.c
> +++ b/android/client/if-bt.c
> @@ -94,6 +94,7 @@ static int remote_devices_capacity = 0;
>  void add_remote_device(const bt_bdaddr_t *addr)
>  {
>  	int i;
> +	bt_bdaddr_t *tmp = NULL;
>  
>  	if (remote_devices == NULL) {
>  		remote_devices = malloc(4 * sizeof(bt_bdaddr_t));
> @@ -119,9 +120,17 @@ void add_remote_device(const bt_bdaddr_t *addr)
>  	/* Realloc space if needed */
>  	if (remote_devices_cnt >= remote_devices_capacity) {
>  		remote_devices_capacity *= 2;
> +		/*
> +		 * Save reference to previously allocated memory block so that
> +		 * it can be freed in case realloc fails.
> +		 */
> +		tmp = remote_devices;
> +
>  		remote_devices = realloc(remote_devices, sizeof(bt_bdaddr_t) *
>  						remote_devices_capacity);
>  		if (remote_devices == NULL) {
> +			if (NULL != tmp)
> +				free(tmp);
>  			remote_devices_capacity = 0;
>  			remote_devices_cnt = 0;
>  			return;
> -- 
> 2.1.4
> 

Re: [PATCH] android/client/if-bt.c: Fix memory leak while using realloc()

[Szymon Janc]

Hi Atul,

On Tuesday 21 of July 2015 17:31:44 Atul Rai wrote:
> ping

I looks like I never got the original patch.

> > ------- Original Message -------
> > Sender : Atul Kumar Rai<a.rai@samsung.com> Lead Engineer (1)/SRI-Delhi-SWC
> > Group/Samsung Electronics Date : Jun 23, 2015 13:38 (GMT+05:30)
> > Title : [PATCH] android/client/if-bt.c: Fix memory leak while using
> > realloc()

Patch prefix "android/client" should be enough.

> > 
> > While reallocating space to store additional "remote device set" using
> > realloc, if realloc() fails, the original block is left untouched but
> > reference to that block is lost as NULL is assigned to remote_devices.
> > The original block needs to be freed before return.
> > 
> > Signed-off-by: Atul Rai <a.rai@samsung.com>

Please remove Signed-off-by as we don't use it for userspace patches.

> > ---
> > 
> >  android/client/if-bt.c | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> > 
> > diff --git a/android/client/if-bt.c b/android/client/if-bt.c
> > index 4723024..4f0c2e9 100644
> > --- a/android/client/if-bt.c
> > +++ b/android/client/if-bt.c
> > @@ -94,6 +94,7 @@ static int remote_devices_capacity = 0;
> > 
> >  void add_remote_device(const bt_bdaddr_t *addr)
> >  {
> >  
> >  	int i;
> > 
> > +	bt_bdaddr_t *tmp = NULL;

No need to initialize it.

> > 
> >  	if (remote_devices == NULL) {
> >  	
> >  		remote_devices = malloc(4 * sizeof(bt_bdaddr_t));
> > 
> > @@ -119,9 +120,17 @@ void add_remote_device(const bt_bdaddr_t *addr)
> > 
> >  	/* Realloc space if needed */
> >  	if (remote_devices_cnt >= remote_devices_capacity) {
> >  	
> >  		remote_devices_capacity *= 2;
> > 
> > +		/*
> > +		 * Save reference to previously allocated memory block so that
> > +		 * it can be freed in case realloc fails.
> > +		 */
> > +		tmp = remote_devices;
> > +
> > 
> >  		remote_devices = realloc(remote_devices, sizeof(bt_bdaddr_t) *
> >  		
> >  						remote_devices_capacity);
> >  		
> >  		if (remote_devices == NULL) {
> > 
> > +			if (NULL != tmp)
> > +				free(tmp);

free() already checks for NULL pointer so no need to double check it.

> > 
> >  			remote_devices_capacity = 0;
> >  			remote_devices_cnt = 0;
> >  			return;
> 
> --
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-- 
BR
Szymon Janc