Re: [PATCH net] bonding: prevent potential infinite loop in bond_header_parse()
From: Jiayuan Chen <hidden>
Date: 2026-03-14 12:05:19
On 3/14/26 7:56 PM, Eric Dumazet wrote:
quoted hunk ↗ jump to hunk
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> Cc: Jiayuan Chen <redacted> Cc: Jay Vosburgh <jv@jvosburgh.net> Cc: Andrew Lunn <andrew+netdev@lunn.ch> --- 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 | 3 ++- net/ipv4/ip_gre.c | 3 ++- net/mac802154/iface.c | 4 +++- net/phonet/af_phonet.c | 5 ++++- 9 files changed, 27 insertions(+), 13 deletions(-)diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c index f1a2bee39bf113fe78f4640ba92a7b4e602c213a..82b3b6d9ed2df6423d5cb7a35282d01775e6cee5 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 707419270ebf217a71b0593880c7a9a1481b7171..33f414d03ab913c58cf2406a4ab25e611c528159 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c@@ -1530,9 +1530,11 @@ 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;@@ -1542,7 +1544,7 @@ 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 9a1eacf35d37087ba8877bf31c017445929041ed..df8f88f63a7063fbd1df5248d2fc02c859a7bc74 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 61b7335aa037c7232a0caa45572043057c02dde3..ca9afa824aa4faf832658043bda6fb430633e476 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 d7aac6f185bcab8a93a204c349272fc7c1b15ee7..7ca01eb3f7d2b22a188502583dc95121adff7cc9 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,@@ -3445,7 +3447,7 @@ 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 13a63b48b7eeb896dfe98eb0070a261eed2c384b..9d159d1cc57d42747f794cdf43fe0ccaf04818b2 100644 --- a/net/ethernet/eth.c +++ b/net/ethernet/eth.c@@ -198,7 +198,8 @@ EXPORT_SYMBOL(eth_type_trans); * @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);diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index e13244729ad8d5b1c2b9c483d25bff0e438134b5..35f0baa99d4092fd499a4795f7f52db33a1fe4e2 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 9e4631fade90c980887803f313727e9ff943bc73..000be60d9580343e40f33ff872ec0aff7daa41d0 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 238a9638d2b0f6a23070b0871515302d8cba864f..d89225d6bfd3bf7668edf3d0fe563f7bbc97de2c 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; }
My bad, I missed the recursion issue with stacked bonds. I reproduced it and verified the fix works correctly. And I will add a test to tools/testing/selftests. Reviewed-by: Jiayuan Chen <redacted> Tested-by: Jiayuan Chen <redacted>