Commit 8498a1c2 authored Dec 18, 2023 by Kuniyuki Iwashima Committed by Zhengchao Shao Dec 18, 2023

ip: Fix data-races around sysctl_ip_no_pmtu_disc.

mainline inclusion
from mainline-v5.19-rc8
commit 0968d2a4
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8P5HO
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0968d2a441bf6afb551fd99e60fa65ed67068963



--------------------------------

While reading sysctl_ip_no_pmtu_disc, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Conflicts:
	net/ipv4/icmp.c
	net/ipv6/af_inet6.c
	net/xfrm/xfrm_state.c

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>

parent 18bfaaff

net/ipv4/af_inet.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -337,7 +337,7 @@ static int inet_create(struct net net, struct socket sock, int protocol,
		inet->hdrincl = 1;
		}

		if (net->ipv4.sysctl_ip_no_pmtu_disc)
		if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
		inet->pmtudisc = IP_PMTUDISC_DONT;
		else
		inet->pmtudisc = IP_PMTUDISC_WANT;

net/ipv4/icmp.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -898,7 +898,7 @@ static bool icmp_unreach(struct sk_buff *skb)
		* values please see
		* Documentation/networking/ip-sysctl.txt
		*/
		switch (net->ipv4.sysctl_ip_no_pmtu_disc) {
		switch (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc)) {
		default:
		net_dbg_ratelimited("%pI4: fragmentation needed and DF set\n",
		&iph->daddr);

net/ipv6/af_inet6.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -231,7 +231,7 @@ static int inet6_create(struct net net, struct socket sock, int protocol,
		inet->mc_list = NULL;
		inet->rcv_tos = 0;

		if (net->ipv4.sysctl_ip_no_pmtu_disc)
		if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
		inet->pmtudisc = IP_PMTUDISC_DONT;
		else
		inet->pmtudisc = IP_PMTUDISC_WANT;