[PATCH 0/2] batman-adv: Adjustments for two function implementations

[PATCH 0/2] batman-adv: Adjustments for two function implementations

[Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 2 Jan 2024 08:02:01 +0100

A few update suggestions were taken into account
from static source code analysis.

Markus Elfring (2):
  Return directly after a failed batadv_dat_select_candidates()
    in batadv_dat_forward_data()
  Improve exception handling in batadv_throw_uevent()

 net/batman-adv/distributed-arp-table.c |  3 +--
 net/batman-adv/main.c                  | 14 ++++++++------
 2 files changed, 9 insertions(+), 8 deletions(-)

--
2.43.0

[PATCH 1/2] batman-adv: Return directly after a failed batadv_dat_select_candidates() in batadv_dat_forward_data()

[Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 2 Jan 2024 07:27:45 +0100

The kfree() function was called in one case by
the batadv_dat_forward_data() function during error handling
even if the passed variable contained a null pointer.
This issue was detected by using the Coccinelle software.

* Thus return directly after a batadv_dat_select_candidates() call failed
  at the beginning.

* Delete the label “out” which became unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 net/batman-adv/distributed-arp-table.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index 28a939d56090..4c7e85534324 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -684,7 +684,7 @@ static bool batadv_dat_forward_data(struct batadv_priv *bat_priv,

 	cand = batadv_dat_select_candidates(bat_priv, ip, vid);
 	if (!cand)
-		goto out;
+		return ret;

 	batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);

@@ -728,7 +728,6 @@ static bool batadv_dat_forward_data(struct batadv_priv *bat_priv,
 		batadv_orig_node_put(cand[i].orig_node);
 	}

-out:
 	kfree(cand);
 	return ret;
 }
--
2.43.0

Re: [PATCH 1/2] batman-adv: Return directly after a failed batadv_dat_select_candidates() in batadv_dat_forward_data()

[Sven Eckelmann]

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On Tuesday, 2 January 2024 08:11:47 CET Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Tue, 2 Jan 2024 07:27:45 +0100
> 
> The kfree() function was called in one case by
> the batadv_dat_forward_data() function during error handling
> even if the passed variable contained a null pointer.
> This issue was detected by using the Coccinelle software.
> 
> * Thus return directly after a batadv_dat_select_candidates() call failed
>   at the beginning.
> 
> * Delete the label “out” which became unnecessary with this refactoring.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Acked-by: Sven Eckelmann <sven@narfation.org>

> ---
>  net/batman-adv/distributed-arp-table.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
> index 28a939d56090..4c7e85534324 100644
> --- a/net/batman-adv/distributed-arp-table.c
> +++ b/net/batman-adv/distributed-arp-table.c
> @@ -684,7 +684,7 @@ static bool batadv_dat_forward_data(struct batadv_priv *bat_priv,
> 
>  	cand = batadv_dat_select_candidates(bat_priv, ip, vid);
>  	if (!cand)
> -		goto out;
> +		return ret;
> 
>  	batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
> 
> @@ -728,7 +728,6 @@ static bool batadv_dat_forward_data(struct batadv_priv *bat_priv,
>  		batadv_orig_node_put(cand[i].orig_node);
>  	}
> 
> -out:
>  	kfree(cand);
>  	return ret;
>  }
> --
> 2.43.0
> 
> 


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[PATCH 2/2] batman-adv: Improve exception handling in batadv_throw_uevent()

[Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Tue, 2 Jan 2024 07:52:21 +0100

The kfree() function was called in up to three cases by
the batadv_throw_uevent() function during error handling
even if the passed variable contained a null pointer.
This issue was detected by using the Coccinelle software.

* Thus adjust jump targets.

* Reorder kfree() calls at the end.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 net/batman-adv/main.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 5fc754b0b3f7..75119f1ffccc 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -691,29 +691,31 @@ int batadv_throw_uevent(struct batadv_priv *bat_priv, enum batadv_uev_type type,
 				  "%s%s", BATADV_UEV_TYPE_VAR,
 				  batadv_uev_type_str[type]);
 	if (!uevent_env[0])
-		goto out;
+		goto report_error;

 	uevent_env[1] = kasprintf(GFP_ATOMIC,
 				  "%s%s", BATADV_UEV_ACTION_VAR,
 				  batadv_uev_action_str[action]);
 	if (!uevent_env[1])
-		goto out;
+		goto free_first_env;

 	/* If the event is DEL, ignore the data field */
 	if (action != BATADV_UEV_DEL) {
 		uevent_env[2] = kasprintf(GFP_ATOMIC,
 					  "%s%s", BATADV_UEV_DATA_VAR, data);
 		if (!uevent_env[2])
-			goto out;
+			goto free_second_env;
 	}

 	ret = kobject_uevent_env(bat_kobj, KOBJ_CHANGE, uevent_env);
-out:
-	kfree(uevent_env[0]);
-	kfree(uevent_env[1]);
 	kfree(uevent_env[2]);
+free_second_env:
+	kfree(uevent_env[1]);
+free_first_env:
+	kfree(uevent_env[0]);

 	if (ret)
+report_error:
 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
 			   "Impossible to send uevent for (%s,%s,%s) event (err: %d)\n",
 			   batadv_uev_type_str[type],
--
2.43.0

Re: [PATCH 2/2] batman-adv: Improve exception handling in batadv_throw_uevent()

[Sven Eckelmann]

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On Tuesday, 2 January 2024 08:12:56 CET Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Tue, 2 Jan 2024 07:52:21 +0100
> 
> The kfree() function was called in up to three cases by
> the batadv_throw_uevent() function during error handling
> even if the passed variable contained a null pointer.
> This issue was detected by using the Coccinelle software.
> 
> * Thus adjust jump targets.
> 
> * Reorder kfree() calls at the end.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Acked-by: Sven Eckelmann <sven@narfation.org>

> ---
>  net/batman-adv/main.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
> index 5fc754b0b3f7..75119f1ffccc 100644
> --- a/net/batman-adv/main.c
> +++ b/net/batman-adv/main.c
> @@ -691,29 +691,31 @@ int batadv_throw_uevent(struct batadv_priv *bat_priv, enum batadv_uev_type type,
>  				  "%s%s", BATADV_UEV_TYPE_VAR,
>  				  batadv_uev_type_str[type]);
>  	if (!uevent_env[0])
> -		goto out;
> +		goto report_error;
> 
>  	uevent_env[1] = kasprintf(GFP_ATOMIC,
>  				  "%s%s", BATADV_UEV_ACTION_VAR,
>  				  batadv_uev_action_str[action]);
>  	if (!uevent_env[1])
> -		goto out;
> +		goto free_first_env;
> 
>  	/* If the event is DEL, ignore the data field */
>  	if (action != BATADV_UEV_DEL) {
>  		uevent_env[2] = kasprintf(GFP_ATOMIC,
>  					  "%s%s", BATADV_UEV_DATA_VAR, data);
>  		if (!uevent_env[2])
> -			goto out;
> +			goto free_second_env;
>  	}
> 
>  	ret = kobject_uevent_env(bat_kobj, KOBJ_CHANGE, uevent_env);
> -out:
> -	kfree(uevent_env[0]);
> -	kfree(uevent_env[1]);
>  	kfree(uevent_env[2]);
> +free_second_env:
> +	kfree(uevent_env[1]);
> +free_first_env:
> +	kfree(uevent_env[0]);
> 
>  	if (ret)
> +report_error:
>  		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
>  			   "Impossible to send uevent for (%s,%s,%s) event (err: %d)\n",
>  			   batadv_uev_type_str[type],
> --
> 2.43.0
> 
> 


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