[PATCH net] igmp, mld: Fix memory leak in igmpv3/mld_del_delrec()

[PATCH net] igmp, mld: Fix memory leak in igmpv3/mld_del_delrec()

[Hangbin Liu]

In function igmpv3/mld_add_delrec() we allocate pmc and put it in
idev->mc_tomb, so we should free it when we don't need it in del_delrec().
But I removed kfree(pmc) incorrectly in latest two patches. Now fix it.

Fixes: 24803f38a5c0 ("igmp: do not remove igmp souce list info when ...")
Fixes: 1666d49e1d41 ("mld: do not remove mld souce list info when ...")
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
 net/ipv4/igmp.c  | 1 +
 net/ipv6/mcast.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 5b15459..44fd86d 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1172,6 +1172,7 @@ static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im)
 				psf->sf_crcount = im->crcount;
 		}
 		in_dev_put(pmc->interface);
+		kfree(pmc);
 	}
 	spin_unlock_bh(&im->lock);
 }
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 7139fff..1bdc703 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -779,6 +779,7 @@ static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
 				psf->sf_crcount = im->mca_crcount;
 		}
 		in6_dev_put(pmc->idev);
+		kfree(pmc);
 	}
 	spin_unlock_bh(&im->mca_lock);
 }
-- 
2.5.5

Re: [PATCH net] igmp, mld: Fix memory leak in igmpv3/mld_del_delrec()

[David Miller]

From: Hangbin Liu <liuhangbin@gmail.com>
Date: Wed,  8 Feb 2017 21:16:45 +0800

> In function igmpv3/mld_add_delrec() we allocate pmc and put it in
> idev->mc_tomb, so we should free it when we don't need it in del_delrec().
> But I removed kfree(pmc) incorrectly in latest two patches. Now fix it.
> 
> Fixes: 24803f38a5c0 ("igmp: do not remove igmp souce list info when ...")
> Fixes: 1666d49e1d41 ("mld: do not remove mld souce list info when ...")
> Reported-by: Daniel Borkmann <daniel@iogearbox.net>
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>

Applied and queued up for -stable, thanks.