Commit 7c1acd98 authored Jul 06, 2022 by Kuniyuki Iwashima Committed by Greg Kroah-Hartman Jul 21, 2022

ipv4: Fix a data-race around sysctl_fib_sync_mem.



[ Upstream commit 73318c4b7dbd0e781aaababff17376b2894745c0 ]

While reading sysctl_fib_sync_mem, it can be changed concurrently.
So, we need to add READ_ONCE() to avoid a data-race.

Fixes: 9ab948a9 ("ipv4: Allow amount of dirty memory from fib resizing to be controllable")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 0cba7ca6

net/ipv4/fib_trie.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -500,7 +500,7 @@ static void tnode_free(struct key_vector *tn)
		tn = container_of(head, struct tnode, rcu)->kv;
		}

		if (tnode_free_size >= sysctl_fib_sync_mem) {
		if (tnode_free_size >= READ_ONCE(sysctl_fib_sync_mem)) {
		tnode_free_size = 0;
		synchronize_rcu();
		}