netdev - [PATCH v2 net-next] ipv6: mcast: Avoid a duplicate pointer check in mld_del

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 linux-cve-announce 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]

Message-ID: <20250714081949.3109947-1-yuehaibing@huawei.com>
Date: Mon, 14 Jul 2025 16:19:49 +0800
From: Yue Haibing <yuehaibing@...wei.com>
To: <davem@...emloft.net>, <dsahern@...nel.org>, <edumazet@...gle.com>,
	<kuba@...nel.org>, <pabeni@...hat.com>, <horms@...nel.org>
CC: <netdev@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<yuehaibing@...wei.com>, <kuniyu@...gle.com>, <Markus.Elfring@....de>
Subject: [PATCH v2 net-next] ipv6: mcast: Avoid a duplicate pointer check in mld_del_delrec()

Avoid duplicate non-null pointer check for pmc in mld_del_delrec().
No functional changes.

Signed-off-by: Yue Haibing <yuehaibing@...wei.com>
---
v2: early return if (!pcm) true as Kuniyuki Iwashima suggested, also revise title
---
 net/ipv6/mcast.c | 52 +++++++++++++++++++++++-------------------------
 1 file changed, 25 insertions(+), 27 deletions(-)

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 6c875721d423..6d737815d0ab 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -789,34 +789,32 @@ static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
 			break;
 		pmc_prev = pmc;
 	}
-	if (pmc) {
-		if (pmc_prev)
-			rcu_assign_pointer(pmc_prev->next, pmc->next);
-		else
-			rcu_assign_pointer(idev->mc_tomb, pmc->next);
-	}
-
-	if (pmc) {
-		im->idev = pmc->idev;
-		if (im->mca_sfmode == MCAST_INCLUDE) {
-			tomb = rcu_replace_pointer(im->mca_tomb,
-						   mc_dereference(pmc->mca_tomb, pmc->idev),
-						   lockdep_is_held(&im->idev->mc_lock));
-			rcu_assign_pointer(pmc->mca_tomb, tomb);
-
-			sources = rcu_replace_pointer(im->mca_sources,
-						      mc_dereference(pmc->mca_sources, pmc->idev),
-						      lockdep_is_held(&im->idev->mc_lock));
-			rcu_assign_pointer(pmc->mca_sources, sources);
-			for_each_psf_mclock(im, psf)
-				psf->sf_crcount = idev->mc_qrv;
-		} else {
-			im->mca_crcount = idev->mc_qrv;
-		}
-		in6_dev_put(pmc->idev);
-		ip6_mc_clear_src(pmc);
-		kfree_rcu(pmc, rcu);
+	if (!pmc)
+		return;
+	if (pmc_prev)
+		rcu_assign_pointer(pmc_prev->next, pmc->next);
+	else
+		rcu_assign_pointer(idev->mc_tomb, pmc->next);
+
+	im->idev = pmc->idev;
+	if (im->mca_sfmode == MCAST_INCLUDE) {
+		tomb = rcu_replace_pointer(im->mca_tomb,
+					   mc_dereference(pmc->mca_tomb, pmc->idev),
+					   lockdep_is_held(&im->idev->mc_lock));
+		rcu_assign_pointer(pmc->mca_tomb, tomb);
+
+		sources = rcu_replace_pointer(im->mca_sources,
+					      mc_dereference(pmc->mca_sources, pmc->idev),
+					      lockdep_is_held(&im->idev->mc_lock));
+		rcu_assign_pointer(pmc->mca_sources, sources);
+		for_each_psf_mclock(im, psf)
+			psf->sf_crcount = idev->mc_qrv;
+	} else {
+		im->mca_crcount = idev->mc_qrv;
 	}
+	in6_dev_put(pmc->idev);
+	ip6_mc_clear_src(pmc);
+	kfree_rcu(pmc, rcu);
 }
 
 static void mld_clear_delrec(struct inet6_dev *idev)
-- 
2.34.1