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Diffstat (limited to 'net')
-rw-r--r--net/ipv4/devinet.c2
-rw-r--r--net/ipv4/igmp.c24
-rw-r--r--net/ipv4/ip_tunnel.c4
3 files changed, 18 insertions, 12 deletions
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 0212591b0077..63f99e9a821b 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1358,7 +1358,7 @@ skip:
static bool inetdev_valid_mtu(unsigned int mtu)
{
- return mtu >= 68;
+ return mtu >= IPV4_MIN_MTU;
}
static void inetdev_send_gratuitous_arp(struct net_device *dev,
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 3809d523d012..6d3497bb3885 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -410,16 +410,17 @@ static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
}
static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
- int type, struct igmpv3_grec **ppgr)
+ int type, struct igmpv3_grec **ppgr, unsigned int mtu)
{
struct net_device *dev = pmc->interface->dev;
struct igmpv3_report *pih;
struct igmpv3_grec *pgr;
- if (!skb)
- skb = igmpv3_newpack(dev, dev->mtu);
- if (!skb)
- return NULL;
+ if (!skb) {
+ skb = igmpv3_newpack(dev, mtu);
+ if (!skb)
+ return NULL;
+ }
pgr = (struct igmpv3_grec *)skb_put(skb, sizeof(struct igmpv3_grec));
pgr->grec_type = type;
pgr->grec_auxwords = 0;
@@ -441,12 +442,17 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
struct igmpv3_grec *pgr = NULL;
struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
int scount, stotal, first, isquery, truncate;
+ unsigned int mtu;
if (pmc->multiaddr == IGMP_ALL_HOSTS)
return skb;
if (ipv4_is_local_multicast(pmc->multiaddr) && !sysctl_igmp_llm_reports)
return skb;
+ mtu = READ_ONCE(dev->mtu);
+ if (mtu < IPV4_MIN_MTU)
+ return skb;
+
isquery = type == IGMPV3_MODE_IS_INCLUDE ||
type == IGMPV3_MODE_IS_EXCLUDE;
truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
@@ -467,7 +473,7 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
if (skb)
igmpv3_sendpack(skb);
- skb = igmpv3_newpack(dev, dev->mtu);
+ skb = igmpv3_newpack(dev, mtu);
}
}
first = 1;
@@ -494,12 +500,12 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
pgr->grec_nsrcs = htons(scount);
if (skb)
igmpv3_sendpack(skb);
- skb = igmpv3_newpack(dev, dev->mtu);
+ skb = igmpv3_newpack(dev, mtu);
first = 1;
scount = 0;
}
if (first) {
- skb = add_grhead(skb, pmc, type, &pgr);
+ skb = add_grhead(skb, pmc, type, &pgr, mtu);
first = 0;
}
if (!skb)
@@ -533,7 +539,7 @@ empty_source:
igmpv3_sendpack(skb);
skb = NULL; /* add_grhead will get a new one */
}
- skb = add_grhead(skb, pmc, type, &pgr);
+ skb = add_grhead(skb, pmc, type, &pgr, mtu);
}
}
if (pgr)
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 3310ac75e3f3..c18245e05d26 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -400,8 +400,8 @@ static int ip_tunnel_bind_dev(struct net_device *dev)
dev->needed_headroom = t_hlen + hlen;
mtu -= (dev->hard_header_len + t_hlen);
- if (mtu < 68)
- mtu = 68;
+ if (mtu < IPV4_MIN_MTU)
+ mtu = IPV4_MIN_MTU;
return mtu;
}