1 files changed, 31 insertions, 22 deletions

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 6c2febc39dca..a57f0d69eadb 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *	Linux NET3:	Internet Group Management Protocol  [IGMP]
  *
@@ -11,11 +12,6 @@
  *	Authors:
  *		Alan Cox <alan@lxorguk.ukuu.org.uk>
  *
- *	This program is free software; you can redistribute it and/or
- *	modify it under the terms of the GNU General Public License
- *	as published by the Free Software Foundation; either version
- *	2 of the License, or (at your option) any later version.
- *
  *	Fixes:
  *
  *		Alan Cox	:	Added lots of __inline__ to optimise
@@ -188,6 +184,17 @@ static void ip_ma_put(struct ip_mc_list *im)
 	     pmc != NULL;					\
 	     pmc = rtnl_dereference(pmc->next_rcu))
 
+static void ip_sf_list_clear_all(struct ip_sf_list *psf)
+{
+	struct ip_sf_list *next;
+
+	while (psf) {
+		next = psf->sf_next;
+		kfree(psf);
+		psf = next;
+	}
+}
+
 #ifdef CONFIG_IP_MULTICAST
 
 /*
@@ -633,6 +640,13 @@ static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
 	}
 }
 
+static void kfree_pmc(struct ip_mc_list *pmc)
+{
+	ip_sf_list_clear_all(pmc->sources);
+	ip_sf_list_clear_all(pmc->tomb);
+	kfree(pmc);
+}
+
 static void igmpv3_send_cr(struct in_device *in_dev)
 {
 	struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
@@ -669,7 +683,7 @@ static void igmpv3_send_cr(struct in_device *in_dev)
 			else
 				in_dev->mc_tomb = pmc_next;
 			in_dev_put(pmc->interface);
-			kfree(pmc);
+			kfree_pmc(pmc);
 		} else
 			pmc_prev = pmc;
 	}
@@ -1215,14 +1229,18 @@ static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im)
 		im->interface = pmc->interface;
 		if (im->sfmode == MCAST_INCLUDE) {
 			im->tomb = pmc->tomb;
+			pmc->tomb = NULL;
+
 			im->sources = pmc->sources;
+			pmc->sources = NULL;
+
 			for (psf = im->sources; psf; psf = psf->sf_next)
 				psf->sf_crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
 		} else {
 			im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv;
 		}
 		in_dev_put(pmc->interface);
-		kfree(pmc);
+		kfree_pmc(pmc);
 	}
 	spin_unlock_bh(&im->lock);
 }
@@ -1243,21 +1261,18 @@ static void igmpv3_clear_delrec(struct in_device *in_dev)
 		nextpmc = pmc->next;
 		ip_mc_clear_src(pmc);
 		in_dev_put(pmc->interface);
-		kfree(pmc);
+		kfree_pmc(pmc);
 	}
 	/* clear dead sources, too */
 	rcu_read_lock();
 	for_each_pmc_rcu(in_dev, pmc) {
-		struct ip_sf_list *psf, *psf_next;
+		struct ip_sf_list *psf;
 
 		spin_lock_bh(&pmc->lock);
 		psf = pmc->tomb;
 		pmc->tomb = NULL;
 		spin_unlock_bh(&pmc->lock);
-		for (; psf; psf = psf_next) {
-			psf_next = psf->sf_next;
-			kfree(psf);
-		}
+		ip_sf_list_clear_all(psf);
 	}
 	rcu_read_unlock();
 }
@@ -2123,7 +2138,7 @@ static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
 
 static void ip_mc_clear_src(struct ip_mc_list *pmc)
 {
-	struct ip_sf_list *psf, *nextpsf, *tomb, *sources;
+	struct ip_sf_list *tomb, *sources;
 
 	spin_lock_bh(&pmc->lock);
 	tomb = pmc->tomb;
@@ -2135,14 +2150,8 @@ static void ip_mc_clear_src(struct ip_mc_list *pmc)
 	pmc->sfcount[MCAST_EXCLUDE] = 1;
 	spin_unlock_bh(&pmc->lock);
 
-	for (psf = tomb; psf; psf = nextpsf) {
-		nextpsf = psf->sf_next;
-		kfree(psf);
-	}
-	for (psf = sources; psf; psf = nextpsf) {
-		nextpsf = psf->sf_next;
-		kfree(psf);
-	}
+	ip_sf_list_clear_all(tomb);
+	ip_sf_list_clear_all(sources);
 }
 
 /* Join a multicast group