Commit 8d7924ce authored Jul 17, 2021 by Pavel Skripkin Committed by Greg Kroah-Hartman Jul 28, 2021

net: sched: fix memory leak in tcindex_partial_destroy_work



[ Upstream commit f5051bcece50140abd1a11a2d36dc3ec5484fc32 ]

Syzbot reported memory leak in tcindex_set_parms(). The problem was in
non-freed perfect hash in tcindex_partial_destroy_work().

In tcindex_set_parms() new tcindex_data is allocated and some fields from
old one are copied to new one, but not the perfect hash. Since
tcindex_partial_destroy_work() is the destroy function for old
tcindex_data, we need to free perfect hash to avoid memory leak.

Reported-and-tested-by:  <syzbot+f0bbb2287b8993d4fa74@syzkaller.appspotmail.com>
Fixes: 331b7292 ("net: sched: RCU cls_tcindex")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent f38527f1

net/sched/cls_tcindex.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -278,6 +278,8 @@ static int tcindex_filter_result_init(struct tcindex_filter_result *r,
		TCA_TCINDEX_POLICE);
		}

		static void tcindex_free_perfect_hash(struct tcindex_data *cp);

		static void tcindex_partial_destroy_work(struct work_struct *work)
		{
		struct tcindex_data *p = container_of(to_rcu_work(work),
		@@ -285,7 +287,8 @@ static void tcindex_partial_destroy_work(struct work_struct *work)
		rwork);

		rtnl_lock();
		kfree(p->perfect);
		if (p->perfect)
		tcindex_free_perfect_hash(p);
		kfree(p);
		rtnl_unlock();
		}