This is a note to let you know that I've just added the patch titled icmp: Fix a data-race around sysctl_icmp_echo_ignore_all. to the 5.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: icmp-fix-a-data-race-around-sysctl_icmp_echo_ignore_.patch and it can be found in the queue-5.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 8a1c23709734bb1f7b40704a799b474159556809 Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> Date: Mon Jul 11 17:15:22 2022 -0700 icmp: Fix a data-race around sysctl_icmp_echo_ignore_all. [ Upstream commit bb7bb35a63b4812da8e3aff587773678e31d23e3 ] While reading sysctl_icmp_echo_ignore_all, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 97350a38a75d..92eaa96a9ff1 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -990,7 +990,7 @@ static bool icmp_echo(struct sk_buff *skb) net = dev_net(skb_dst(skb)->dev); /* should there be an ICMP stat for ignored echos? */ - if (net->ipv4.sysctl_icmp_echo_ignore_all) + if (READ_ONCE(net->ipv4.sysctl_icmp_echo_ignore_all)) return true; icmp_param.data.icmph = *icmp_hdr(skb); diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index ad80d180b60b..8987864c4479 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -603,6 +603,8 @@ static struct ctl_table ipv4_net_table[] = { .maxlen = sizeof(u8), .mode = 0644, .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE }, { .procname = "icmp_echo_enable_probe",