[SRU][B][PATCH 7/7] net_sched: fix two more memory leaks in cls_tcindex

[Andrea Righi]

From: Cong Wang <xiyou.wangcong at gmail.com>

Buglink: https://bugs.launchpad.net/bugs/1825942

struct tcindex_filter_result contains two parts:
struct tcf_exts and struct tcf_result.

For the local variable 'cr', its exts part is never used but
initialized without being released properly on success path. So
just completely remove the exts part to fix this leak.

For the local variable 'new_filter_result', it is never properly
released if not used by 'r' on success path.

Cc: Jamal Hadi Salim <jhs at mojatatu.com>
Cc: Jiri Pirko <jiri at resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong at gmail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit 1db817e75f5b9387b8db11e37d5f0624eb9223e0)
Signed-off-by: Andrea Righi <andrea.righi at canonical.com>
---
 net/sched/cls_tcindex.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index 204e11feabba..41850f0a3910 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -302,9 +302,9 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 		  struct nlattr *est, bool ovr)
 {
 	struct tcindex_filter_result new_filter_result, *old_r = r;
-	struct tcindex_filter_result cr;
 	struct tcindex_data *cp = NULL, *oldp;
 	struct tcindex_filter *f = NULL; /* make gcc behave */
+	struct tcf_result cr = {};
 	int err, balloc = 0;
 	struct tcf_exts e;
 
@@ -343,13 +343,10 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 	cp->h = p->h;
 
 	err = tcindex_filter_result_init(&new_filter_result, net);
-	if (err < 0)
-		goto errout1;
-	err = tcindex_filter_result_init(&cr);
 	if (err < 0)
 		goto errout1;
 	if (old_r)
-		cr.res = r->res;
+		cr = r->res;
 
 	if (tb[TCA_TCINDEX_HASH])
 		cp->hash = nla_get_u32(tb[TCA_TCINDEX_HASH]);
@@ -440,8 +437,8 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 	}
 
 	if (tb[TCA_TCINDEX_CLASSID]) {
-		cr.res.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]);
-		tcf_bind_filter(tp, &cr.res, base);
+		cr.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]);
+		tcf_bind_filter(tp, &cr, base);
 	}
 
 	if (old_r && old_r != r) {
@@ -453,7 +450,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 	}
 
 	oldp = p;
-	r->res = cr.res;
+	r->res = cr;
 	tcf_exts_change(&r->exts, &e);
 
 	rcu_assign_pointer(tp->root, cp);
@@ -471,6 +468,8 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 				; /* nothing */
 
 		rcu_assign_pointer(*fp, f);
+	} else {
+		tcf_exts_destroy(&new_filter_result.exts);
 	}
 
 	if (oldp)
@@ -483,7 +482,6 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 	else if (balloc == 2)
 		kfree(cp->h);
 errout1:
-	tcf_exts_destroy(&cr.exts);
 	tcf_exts_destroy(&new_filter_result.exts);
 errout:
 	kfree(cp);
-- 
2.17.1