ip: Fix data-races around sysctl_ip_no_pmtu_disc.

[ Upstream commit 0968d2a441 ]

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

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
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>
This commit is contained in:
Kuniyuki Iwashima 2022-07-13 13:51:52 -07:00 committed by Greg Kroah-Hartman
parent 70965b6e5c
commit a09ae9091e
4 changed files with 4 additions and 4 deletions

View File

@ -335,7 +335,7 @@ lookup_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;

View File

@ -878,7 +878,7 @@ static bool icmp_unreach(struct sk_buff *skb)
* values please see
* Documentation/networking/ip-sysctl.rst
*/
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);

View File

@ -226,7 +226,7 @@ lookup_protocol:
RCU_INIT_POINTER(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;

View File

@ -2620,7 +2620,7 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload)
int err;
if (family == AF_INET &&
xs_net(x)->ipv4.sysctl_ip_no_pmtu_disc)
READ_ONCE(xs_net(x)->ipv4.sysctl_ip_no_pmtu_disc))
x->props.flags |= XFRM_STATE_NOPMTUDISC;
err = -EPROTONOSUPPORT;