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-rw-r--r--net/ethtool/netlink.h26
-rw-r--r--net/ipv4/fib_semantics.c2
-rw-r--r--net/ipv4/metrics.c2
-rw-r--r--net/ipv6/ip6_output.c15
-rw-r--r--net/netlink/af_netlink.c38
5 files changed, 68 insertions, 15 deletions
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 3753787ba233..744b3ab966b0 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -112,6 +112,32 @@ static inline void ethnl_update_u8(u8 *dst, const struct nlattr *attr,
}
/**
+ * ethnl_update_bool() - update bool from NLA_U8 attribute
+ * @dst: value to update
+ * @attr: netlink attribute with new value or null
+ * @mod: pointer to bool for modification tracking
+ *
+ * Use the u8 value from NLA_U8 netlink attribute @attr to set bool variable
+ * pointed to by @dst to false (if zero) or 1 (if not); do nothing if @attr is
+ * null. Bool pointed to by @mod is set to true if this function changed the
+ * logical value of *dst, otherwise it is left as is.
+ */
+static inline void ethnl_update_bool(bool *dst, const struct nlattr *attr,
+ bool *mod)
+{
+ u8 val;
+
+ if (!attr)
+ return;
+ val = !!nla_get_u8(attr);
+ if (*dst == val)
+ return;
+
+ *dst = val;
+ *mod = true;
+}
+
+/**
* ethnl_update_bool32() - update u32 used as bool from NLA_U8 attribute
* @dst: value to update
* @attr: netlink attribute with new value or null
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index ce9ff3c62e84..3bb890a40ed7 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -30,6 +30,7 @@
#include <linux/slab.h>
#include <linux/netlink.h>
#include <linux/hash.h>
+#include <linux/nospec.h>
#include <net/arp.h>
#include <net/inet_dscp.h>
@@ -1022,6 +1023,7 @@ bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi)
if (type > RTAX_MAX)
return false;
+ type = array_index_nospec(type, RTAX_MAX + 1);
if (type == RTAX_CC_ALGO) {
char tmp[TCP_CA_NAME_MAX];
bool ecn_ca = false;
diff --git a/net/ipv4/metrics.c b/net/ipv4/metrics.c
index 7fcfdfd8f9de..0e3ee1532848 100644
--- a/net/ipv4/metrics.c
+++ b/net/ipv4/metrics.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/netlink.h>
+#include <linux/nospec.h>
#include <linux/rtnetlink.h>
#include <linux/types.h>
#include <net/ip.h>
@@ -25,6 +26,7 @@ static int ip_metrics_convert(struct net *net, struct nlattr *fc_mx,
return -EINVAL;
}
+ type = array_index_nospec(type, RTAX_MAX + 1);
if (type == RTAX_CC_ALGO) {
char tmp[TCP_CA_NAME_MAX];
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 60fd91bb5171..c314fdde0097 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -547,7 +547,20 @@ int ip6_forward(struct sk_buff *skb)
pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) {
int proxied = ip6_forward_proxy_check(skb);
if (proxied > 0) {
- hdr->hop_limit--;
+ /* It's tempting to decrease the hop limit
+ * here by 1, as we do at the end of the
+ * function too.
+ *
+ * But that would be incorrect, as proxying is
+ * not forwarding. The ip6_input function
+ * will handle this packet locally, and it
+ * depends on the hop limit being unchanged.
+ *
+ * One example is the NDP hop limit, that
+ * always has to stay 255, but other would be
+ * similar checks around RA packets, where the
+ * user can even change the desired limit.
+ */
return ip6_input(skb);
} else if (proxied < 0) {
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index bca2a470ccad..c64277659753 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -580,7 +580,9 @@ static int netlink_insert(struct sock *sk, u32 portid)
if (nlk_sk(sk)->bound)
goto err;
- nlk_sk(sk)->portid = portid;
+ /* portid can be read locklessly from netlink_getname(). */
+ WRITE_ONCE(nlk_sk(sk)->portid, portid);
+
sock_hold(sk);
err = __netlink_insert(table, sk);
@@ -1096,9 +1098,11 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
return -EINVAL;
if (addr->sa_family == AF_UNSPEC) {
- sk->sk_state = NETLINK_UNCONNECTED;
- nlk->dst_portid = 0;
- nlk->dst_group = 0;
+ /* paired with READ_ONCE() in netlink_getsockbyportid() */
+ WRITE_ONCE(sk->sk_state, NETLINK_UNCONNECTED);
+ /* dst_portid and dst_group can be read locklessly */
+ WRITE_ONCE(nlk->dst_portid, 0);
+ WRITE_ONCE(nlk->dst_group, 0);
return 0;
}
if (addr->sa_family != AF_NETLINK)
@@ -1119,9 +1123,11 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
err = netlink_autobind(sock);
if (err == 0) {
- sk->sk_state = NETLINK_CONNECTED;
- nlk->dst_portid = nladdr->nl_pid;
- nlk->dst_group = ffs(nladdr->nl_groups);
+ /* paired with READ_ONCE() in netlink_getsockbyportid() */
+ WRITE_ONCE(sk->sk_state, NETLINK_CONNECTED);
+ /* dst_portid and dst_group can be read locklessly */
+ WRITE_ONCE(nlk->dst_portid, nladdr->nl_pid);
+ WRITE_ONCE(nlk->dst_group, ffs(nladdr->nl_groups));
}
return err;
@@ -1138,10 +1144,12 @@ static int netlink_getname(struct socket *sock, struct sockaddr *addr,
nladdr->nl_pad = 0;
if (peer) {
- nladdr->nl_pid = nlk->dst_portid;
- nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
+ /* Paired with WRITE_ONCE() in netlink_connect() */
+ nladdr->nl_pid = READ_ONCE(nlk->dst_portid);
+ nladdr->nl_groups = netlink_group_mask(READ_ONCE(nlk->dst_group));
} else {
- nladdr->nl_pid = nlk->portid;
+ /* Paired with WRITE_ONCE() in netlink_insert() */
+ nladdr->nl_pid = READ_ONCE(nlk->portid);
netlink_lock_table();
nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
netlink_unlock_table();
@@ -1168,8 +1176,9 @@ static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
/* Don't bother queuing skb if kernel socket has no input function */
nlk = nlk_sk(sock);
- if (sock->sk_state == NETLINK_CONNECTED &&
- nlk->dst_portid != nlk_sk(ssk)->portid) {
+ /* dst_portid and sk_state can be changed in netlink_connect() */
+ if (READ_ONCE(sock->sk_state) == NETLINK_CONNECTED &&
+ READ_ONCE(nlk->dst_portid) != nlk_sk(ssk)->portid) {
sock_put(sock);
return ERR_PTR(-ECONNREFUSED);
}
@@ -1886,8 +1895,9 @@ static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
goto out;
netlink_skb_flags |= NETLINK_SKB_DST;
} else {
- dst_portid = nlk->dst_portid;
- dst_group = nlk->dst_group;
+ /* Paired with WRITE_ONCE() in netlink_connect() */
+ dst_portid = READ_ONCE(nlk->dst_portid);
+ dst_group = READ_ONCE(nlk->dst_group);
}
/* Paired with WRITE_ONCE() in netlink_insert() */
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-19 09:50:49 +0000