[PATCH 6.19 148/220] bonding: prevent potential infinite loop in bond_header_parse()

Greg Kroah-Hartman
2026-03-23T13:57:01Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit b7405dcf7385445e10821777143f18c3ce20fa04 ]

bond_header_parse() can loop if a stack of two bonding devices is setup,
because skb->dev always points to the hierarchy top.

Add new "const struct net_device *dev" parameter to
(struct header_ops)->parse() method to make sure the recursion
is bounded, and that the final leaf parse method is called.

Fixes: 950803f72547 ("bonding: fix type confusion in bond_setup_by_slave()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Tested-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Cc: Jay Vosburgh <jv@jvosburgh.net>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
Link: https://patch.msgid.link/20260315104152.1436867-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/firewire/net.c | 5 +++--
drivers/net/bonding/bond_main.c | 8 +++++---
include/linux/etherdevice.h | 3 ++-
include/linux/if_ether.h | 3 ++-
include/linux/netdevice.h | 6 ++++--
net/ethernet/eth.c | 9 +++------
net/ipv4/ip_gre.c | 3 ++-
net/mac802154/iface.c | 4 +++-
net/phonet/af_phonet.c | 5 ++++-
9 files changed, 28 insertions(+), 18 deletions(-)

diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c
index 6d64467135395..e829454089550 100644
--- a/drivers/firewire/net.c
+++ b/drivers/firewire/net.c
@@ -257,9 +257,10 @@ static void fwnet_header_cache_update(struct hh_cache *hh,
memcpy((u8 *)hh->hh_data + HH_DATA_OFF(FWNET_HLEN), haddr, net->addr_len);
}

-static int fwnet_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+static int fwnet_header_parse(const struct sk_buff *skb, const struct net_device *dev,
+ unsigned char *haddr)
{
- memcpy(haddr, skb->dev->dev_addr, FWNET_ALEN);
+ memcpy(haddr, dev->dev_addr, FWNET_ALEN);

return FWNET_ALEN;
}
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index e8e261e0cb4e1..106cfe732a15e 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1497,9 +1497,11 @@ static int bond_header_create(struct sk_buff *skb, struct net_device *bond_dev,
return ret;
}

-static int bond_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+static int bond_header_parse(const struct sk_buff *skb,
+ const struct net_device *dev,
+ unsigned char *haddr)
{
- struct bonding *bond = netdev_priv(skb->dev);
+ struct bonding *bond = netdev_priv(dev);
const struct header_ops *slave_ops;
struct slave *slave;
int ret = 0;
@@ -1509,7 +1511,7 @@ static int bond_header_parse(const struct sk_buff *skb, unsigned char *haddr)
if (slave) {
slave_ops = READ_ONCE(slave->dev->header_ops);
if (slave_ops && slave_ops->parse)
- ret = slave_ops->parse(skb, haddr);
+ ret = slave_ops->parse(skb, slave->dev, haddr);
}
rcu_read_unlock();
return ret;
diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h
index 9a1eacf35d370..df8f88f63a706 100644
--- a/include/linux/etherdevice.h
+++ b/include/linux/etherdevice.h
@@ -42,7 +42,8 @@ extern const struct header_ops eth_header_ops;

int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
const void *daddr, const void *saddr, unsigned len);
-int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
+int eth_header_parse(const struct sk_buff *skb, const struct net_device *dev,
+ unsigned char *haddr);
int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
__be16 type);
void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev,
diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h
index 61b7335aa037c..ca9afa824aa4f 100644
--- a/include/linux/if_ether.h
+++ b/include/linux/if_ether.h
@@ -40,7 +40,8 @@ static inline struct ethhdr *inner_eth_hdr(const struct sk_buff *skb)
return (struct ethhdr *)skb_inner_mac_header(skb);
}

-int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
+int eth_header_parse(const struct sk_buff *skb, const struct net_device *dev,
+ unsigned char *haddr);

extern ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len);

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 444e52eb8ed99..1216f050f0699 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -311,7 +311,9 @@ struct header_ops {
int (*create) (struct sk_buff *skb, struct net_device *dev,
unsigned short type, const void *daddr,
const void *saddr, unsigned int len);
- int (*parse)(const struct sk_buff *skb, unsigned char *haddr);
+ int (*parse)(const struct sk_buff *skb,
+ const struct net_device *dev,
+ unsigned char *haddr);
int (*cache)(const struct neighbour *neigh, struct hh_cache *hh, __be16 type);
void (*cache_update)(struct hh_cache *hh,
const struct net_device *dev,
@@ -3442,7 +3444,7 @@ static inline int dev_parse_header(const struct sk_buff *skb,

if (!dev->header_ops || !dev->header_ops->parse)
return 0;
- return dev->header_ops->parse(skb, haddr);
+ return dev->header_ops->parse(skb, dev, haddr);
}

static inline __be16 dev_parse_header_protocol(const struct sk_buff *skb)
diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c
index 13a63b48b7eeb..d9faadbe9b6c8 100644
--- a/net/ethernet/eth.c
+++ b/net/ethernet/eth.c
@@ -193,14 +193,11 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)
}
EXPORT_SYMBOL(eth_type_trans);

-/**
- * eth_header_parse - extract hardware address from packet
- * @skb: packet to extract header from
- * @haddr: destination buffer
- */
-int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+int eth_header_parse(const struct sk_buff *skb, const struct net_device *dev,
+ unsigned char *haddr)
{
const struct ethhdr *eth = eth_hdr(skb);
+
memcpy(haddr, eth->h_source, ETH_ALEN);
return ETH_ALEN;
}
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index e13244729ad8d..35f0baa99d409 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -919,7 +919,8 @@ static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
return -(t->hlen + sizeof(*iph));
}

-static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+static int ipgre_header_parse(const struct sk_buff *skb, const struct net_device *dev,
+ unsigned char *haddr)
{
const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
memcpy(haddr, &iph->saddr, 4);
diff --git a/net/mac802154/iface.c b/net/mac802154/iface.c
index 9e4631fade90c..000be60d95803 100644
--- a/net/mac802154/iface.c
+++ b/net/mac802154/iface.c
@@ -469,7 +469,9 @@ static int mac802154_header_create(struct sk_buff *skb,
}

static int
-mac802154_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+mac802154_header_parse(const struct sk_buff *skb,
+ const struct net_device *dev,
+ unsigned char *haddr)
{
struct ieee802154_hdr hdr;

diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c
index 238a9638d2b0f..d89225d6bfd3b 100644
--- a/net/phonet/af_phonet.c
+++ b/net/phonet/af_phonet.c
@@ -129,9 +129,12 @@ static int pn_header_create(struct sk_buff *skb, struct net_device *dev,
return 1;
}

-static int pn_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+static int pn_header_parse(const struct sk_buff *skb,
+ const struct net_device *dev,
+ unsigned char *haddr)
{
const u8 *media = skb_mac_header(skb);
+
*haddr = *media;
return 1;
}
--
2.51.0