netdev - [PATCH] net: dsa: bcm_sf2_cfp: fix an incorrect NULL check on list iterator

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 28 Mar 2022 11:24:31 +0800
From:   Xiaomeng Tong <xiam0nd.tong@...il.com>
To:     f.fainelli@...il.com
Cc:     andrew@...n.ch, vivien.didelot@...il.com, olteanv@...il.com,
        davem@...emloft.net, kuba@...nel.org, pabeni@...hat.com,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        Xiaomeng Tong <xiam0nd.tong@...il.com>
Subject: [PATCH] net: dsa: bcm_sf2_cfp: fix an incorrect NULL check on list iterator

The bug is here:
	return rule;

The list iterator value 'rule' will *always* be set and non-NULL
by list_for_each_entry(), so it is incorrect to assume that the
iterator value will be NULL if the list is empty or no element
is found.

To fix the bug, return 'rule' when found, otherwise return NULL.

Fixes: ae7a5aff783c7 ("net: dsa: bcm_sf2: Keep copy of inserted rules")
Reviewed-by: Vladimir Oltean <olteanv@...il.com>
Reviewed-by: Florian Fainelli <f.fainelli@...il.com>
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@...il.com>
---
 drivers/net/dsa/bcm_sf2_cfp.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dsa/bcm_sf2_cfp.c b/drivers/net/dsa/bcm_sf2_cfp.c
index a7e2fcf2df2c..edbe5e7f1cb6 100644
--- a/drivers/net/dsa/bcm_sf2_cfp.c
+++ b/drivers/net/dsa/bcm_sf2_cfp.c
@@ -567,14 +567,14 @@ static void bcm_sf2_cfp_slice_ipv6(struct bcm_sf2_priv *priv,
 static struct cfp_rule *bcm_sf2_cfp_rule_find(struct bcm_sf2_priv *priv,
 					      int port, u32 location)
 {
-	struct cfp_rule *rule = NULL;
+	struct cfp_rule *rule;
 
 	list_for_each_entry(rule, &priv->cfp.rules_list, next) {
 		if (rule->port == port && rule->fs.location == location)
-			break;
+			return rule;
 	}
 
-	return rule;
+	return NULL;
 }
 
 static int bcm_sf2_cfp_rule_cmp(struct bcm_sf2_priv *priv, int port,
-- 
2.17.1