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From:   Xiu Jianfeng <xiujianfeng@huawei.com>
To:     <jmorris@namei.org>, <serge@hallyn.com>
CC:     <linux-security-module@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: [PATCH -next] lsm_audit: Clean up redundant NULL pointer check
Date:   Tue, 14 Jun 2022 20:10:30 +0800
Message-ID: <20220614121030.115491-1-xiujianfeng@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

The implements of {ip,tcp,udp,dccp,sctp,ipv6}_hdr(skb) guarantee that
they will never return NULL, and elsewhere user don't do the check
as well, so remove the check here.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
---
 security/lsm_audit.c | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/security/lsm_audit.c b/security/lsm_audit.c
index 78a278f28e49..75cc3f8d2a42 100644
--- a/security/lsm_audit.c
+++ b/security/lsm_audit.c
@@ -44,9 +44,6 @@ int ipv4_skb_to_auditdata(struct sk_buff *skb,
 	struct iphdr *ih;
 
 	ih = ip_hdr(skb);
-	if (ih == NULL)
-		return -EINVAL;
-
 	ad->u.net->v4info.saddr = ih->saddr;
 	ad->u.net->v4info.daddr = ih->daddr;
 
@@ -59,8 +56,6 @@ int ipv4_skb_to_auditdata(struct sk_buff *skb,
 	switch (ih->protocol) {
 	case IPPROTO_TCP: {
 		struct tcphdr *th = tcp_hdr(skb);
-		if (th == NULL)
-			break;
 
 		ad->u.net->sport = th->source;
 		ad->u.net->dport = th->dest;
@@ -68,8 +63,6 @@ int ipv4_skb_to_auditdata(struct sk_buff *skb,
 	}
 	case IPPROTO_UDP: {
 		struct udphdr *uh = udp_hdr(skb);
-		if (uh == NULL)
-			break;
 
 		ad->u.net->sport = uh->source;
 		ad->u.net->dport = uh->dest;
@@ -77,8 +70,6 @@ int ipv4_skb_to_auditdata(struct sk_buff *skb,
 	}
 	case IPPROTO_DCCP: {
 		struct dccp_hdr *dh = dccp_hdr(skb);
-		if (dh == NULL)
-			break;
 
 		ad->u.net->sport = dh->dccph_sport;
 		ad->u.net->dport = dh->dccph_dport;
@@ -86,8 +77,7 @@ int ipv4_skb_to_auditdata(struct sk_buff *skb,
 	}
 	case IPPROTO_SCTP: {
 		struct sctphdr *sh = sctp_hdr(skb);
-		if (sh == NULL)
-			break;
+
 		ad->u.net->sport = sh->source;
 		ad->u.net->dport = sh->dest;
 		break;
@@ -115,8 +105,6 @@ int ipv6_skb_to_auditdata(struct sk_buff *skb,
 	__be16 frag_off;
 
 	ip6 = ipv6_hdr(skb);
-	if (ip6 == NULL)
-		return -EINVAL;
 	ad->u.net->v6info.saddr = ip6->saddr;
 	ad->u.net->v6info.daddr = ip6->daddr;
 	/* IPv6 can have several extension header before the Transport header
-- 
2.17.1