From: Kuniyuki Iwashima <kuniyu@amazon.com> stable inclusion from stable-v5.10.132 commit 418b191d5f223a8cb6cab09eae1f72c04ba6adf2 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5YS3T Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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: 9ab948a91b2c ("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> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Acked-by: Xie XiuQi <xiexiuqi@huawei.com> --- net/ipv4/fib_trie.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index ffc5332f1390..a28f525e2c47 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -497,7 +497,7 @@ 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(); } -- 2.20.1