From d3e6e285fff3494a5c12154c8e7d79f5181d3ddc Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 3 Jun 2019 22:41:44 +0200 Subject: [PATCH] net: ipv4: fix rcu lockdep splat due to wrong annotation syzbot triggered following splat when strict netlink validation is enabled: net/ipv4/devinet.c:1766 suspicious rcu_dereference_check() usage! This occurs because we hold RTNL mutex, but no rcu read lock. The second call site holds both, so just switch to the _rtnl variant. Reported-by: syzbot+bad6e32808a3a97b1515@syzkaller.appspotmail.com Fixes: 2638eb8b50cf ("net: ipv4: provide __rcu annotation for ifa_list") Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- net/ipv4/devinet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index ebaea05b4033..ed2e2dc745cd 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -1763,7 +1763,7 @@ static int in_dev_dump_addr(struct in_device *in_dev, struct sk_buff *skb, int ip_idx = 0; int err; - in_dev_for_each_ifa_rcu(ifa, in_dev) { + in_dev_for_each_ifa_rtnl(ifa, in_dev) { if (ip_idx < s_ip_idx) { ip_idx++; continue;