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authorKuniyuki Iwashima <kuniyu@amazon.com>2022-07-13 22:51:51 +0200
committerDavid S. Miller <davem@davemloft.net>2022-07-15 12:49:55 +0200
commit8281b7ec5c56b71cb2cc5a1728b41607be66959c (patch)
tree1c9563f175e6e4528ca2f2d33256c18efca097bb /net/ipv4
parentx86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current (diff)
downloadlinux-8281b7ec5c56b71cb2cc5a1728b41607be66959c.tar.xz
linux-8281b7ec5c56b71cb2cc5a1728b41607be66959c.zip
ip: Fix data-races around sysctl_ip_default_ttl.
While reading sysctl_ip_default_ttl, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/ip_sockglue.c2
-rw-r--r--net/ipv4/netfilter/nf_reject_ipv4.c4
-rw-r--r--net/ipv4/proc.c2
3 files changed, 4 insertions, 4 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 445a9ecaefa1..d497d525dea3 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1606,7 +1606,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
{
struct net *net = sock_net(sk);
val = (inet->uc_ttl == -1 ?
- net->ipv4.sysctl_ip_default_ttl :
+ READ_ONCE(net->ipv4.sysctl_ip_default_ttl) :
inet->uc_ttl);
break;
}
diff --git a/net/ipv4/netfilter/nf_reject_ipv4.c b/net/ipv4/netfilter/nf_reject_ipv4.c
index 918c61fda0f3..d640adcaf1b1 100644
--- a/net/ipv4/netfilter/nf_reject_ipv4.c
+++ b/net/ipv4/netfilter/nf_reject_ipv4.c
@@ -62,7 +62,7 @@ struct sk_buff *nf_reject_skb_v4_tcp_reset(struct net *net,
skb_reserve(nskb, LL_MAX_HEADER);
niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_TCP,
- net->ipv4.sysctl_ip_default_ttl);
+ READ_ONCE(net->ipv4.sysctl_ip_default_ttl));
nf_reject_ip_tcphdr_put(nskb, oldskb, oth);
niph->tot_len = htons(nskb->len);
ip_send_check(niph);
@@ -117,7 +117,7 @@ struct sk_buff *nf_reject_skb_v4_unreach(struct net *net,
skb_reserve(nskb, LL_MAX_HEADER);
niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_ICMP,
- net->ipv4.sysctl_ip_default_ttl);
+ READ_ONCE(net->ipv4.sysctl_ip_default_ttl));
skb_reset_transport_header(nskb);
icmph = skb_put_zero(nskb, sizeof(struct icmphdr));
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 28836071f0a6..0088a4c64d77 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -387,7 +387,7 @@ static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
seq_printf(seq, "\nIp: %d %d",
IPV4_DEVCONF_ALL(net, FORWARDING) ? 1 : 2,
- net->ipv4.sysctl_ip_default_ttl);
+ READ_ONCE(net->ipv4.sysctl_ip_default_ttl));
BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,