6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit 4b8474a0951e605d2a27a2c483da4eb4b8c63760 ]
__icmp_send() must ensure rcu_read_lock() is held, as spotted
by Jakub.
Other ICMP uses of dev_net() seem safe, change them to dev_net_rcu()
to get LOCKDEP support.
Fixes: dde1bc0e6f86 ("[NETNS]: Add namespace for ICMP replying code.")
Closes: https://lore.kernel.org/netdev/20250203153633.46ce0337@xxxxxxxxxx/
Reported-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Link: https://patch.msgid.link/20250205155120.1676781-9-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv4/icmp.c | 31 +++++++++++++++++--------------
1 file changed, 17 insertions(+), 14 deletions(-)
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index a6adf6a2ec4b5..a21d32b3ae6c3 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -403,10 +403,10 @@ static void icmp_push_reply(struct sock *sk,
static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
{
- struct ipcm_cookie ipc;
struct rtable *rt = skb_rtable(skb);
- struct net *net = dev_net(rt->dst.dev);
+ struct net *net = dev_net_rcu(rt->dst.dev);
bool apply_ratelimit = false;
+ struct ipcm_cookie ipc;
struct flowi4 fl4;
struct sock *sk;
struct inet_sock *inet;
@@ -609,12 +609,14 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info,
struct sock *sk;
if (!rt)
- goto out;
+ return;
+
+ rcu_read_lock();
if (rt->dst.dev)
- net = dev_net(rt->dst.dev);
+ net = dev_net_rcu(rt->dst.dev);
else if (skb_in->dev)
- net = dev_net(skb_in->dev);
+ net = dev_net_rcu(skb_in->dev);
else
goto out;
@@ -783,7 +785,8 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info,
icmp_xmit_unlock(sk);
out_bh_enable:
local_bh_enable();
-out:;
+out:
+ rcu_read_unlock();
}
EXPORT_SYMBOL(__icmp_send);
@@ -832,7 +835,7 @@ static void icmp_socket_deliver(struct sk_buff *skb, u32 info)
* avoid additional coding at protocol handlers.
*/
if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) {
- __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS);
+ __ICMP_INC_STATS(dev_net_rcu(skb->dev), ICMP_MIB_INERRORS);
return;
}
@@ -866,7 +869,7 @@ static enum skb_drop_reason icmp_unreach(struct sk_buff *skb)
struct net *net;
u32 info = 0;
- net = dev_net(skb_dst(skb)->dev);
+ net = dev_net_rcu(skb_dst(skb)->dev);
/*
* Incomplete header ?
@@ -977,7 +980,7 @@ static enum skb_drop_reason icmp_unreach(struct sk_buff *skb)
static enum skb_drop_reason icmp_redirect(struct sk_buff *skb)
{
if (skb->len < sizeof(struct iphdr)) {
- __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS);
+ __ICMP_INC_STATS(dev_net_rcu(skb->dev), ICMP_MIB_INERRORS);
return SKB_DROP_REASON_PKT_TOO_SMALL;
}
@@ -1009,7 +1012,7 @@ static enum skb_drop_reason icmp_echo(struct sk_buff *skb)
struct icmp_bxm icmp_param;
struct net *net;
- net = dev_net(skb_dst(skb)->dev);
+ net = dev_net_rcu(skb_dst(skb)->dev);
/* should there be an ICMP stat for ignored echos? */
if (READ_ONCE(net->ipv4.sysctl_icmp_echo_ignore_all))
return SKB_NOT_DROPPED_YET;
@@ -1038,9 +1041,9 @@ static enum skb_drop_reason icmp_echo(struct sk_buff *skb)
bool icmp_build_probe(struct sk_buff *skb, struct icmphdr *icmphdr)
{
+ struct net *net = dev_net_rcu(skb->dev);
struct icmp_ext_hdr *ext_hdr, _ext_hdr;
struct icmp_ext_echo_iio *iio, _iio;
- struct net *net = dev_net(skb->dev);
struct inet6_dev *in6_dev;
struct in_device *in_dev;
struct net_device *dev;
@@ -1179,7 +1182,7 @@ static enum skb_drop_reason icmp_timestamp(struct sk_buff *skb)
return SKB_NOT_DROPPED_YET;
out_err:
- __ICMP_INC_STATS(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS);
+ __ICMP_INC_STATS(dev_net_rcu(skb_dst(skb)->dev), ICMP_MIB_INERRORS);
return SKB_DROP_REASON_PKT_TOO_SMALL;
}
@@ -1196,7 +1199,7 @@ int icmp_rcv(struct sk_buff *skb)
{
enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED;
struct rtable *rt = skb_rtable(skb);
- struct net *net = dev_net(rt->dst.dev);
+ struct net *net = dev_net_rcu(rt->dst.dev);
struct icmphdr *icmph;
if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
@@ -1369,9 +1372,9 @@ int icmp_err(struct sk_buff *skb, u32 info)
struct iphdr *iph = (struct iphdr *)skb->data;
int offset = iph->ihl<<2;
struct icmphdr *icmph = (struct icmphdr *)(skb->data + offset);
+ struct net *net = dev_net_rcu(skb->dev);
int type = icmp_hdr(skb)->type;
int code = icmp_hdr(skb)->code;
- struct net *net = dev_net(skb->dev);
/*
* Use ping_err to handle all icmp errors except those
--
2.39.5
