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From: Jiayuan Chen <mrpre@163.com>
To: Eric Dumazet <edumazet@google.com>,
	"David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>,
	netdev@vger.kernel.org, eric.dumazet@gmail.com,
	Jiayuan Chen <jiayuan.chen@shopee.com>,
	Jay Vosburgh <jv@jvosburgh.net>,
	Andrew Lunn <andrew+netdev@lunn.ch>
Subject: Re: [PATCH net] bonding: prevent potential infinite loop in bond_header_parse()
Date: Sat, 14 Mar 2026 20:03:34 +0800	[thread overview]
Message-ID: <03134b09-5bcd-4898-bb2d-d866e1acd97a@163.com> (raw)
In-Reply-To: <20260314115650.3646361-1-edumazet@google.com>


On 3/14/26 7:56 PM, Eric Dumazet wrote:
> 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 <jiayuan.chen@shopee.com>
> 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 <jiayuan.chen@shopee.com>
Tested-by: Jiayuan Chen <jiayuan.chen@shopee.com>


  reply	other threads:[~2026-03-14 12:05 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-14 11:56 [PATCH net] bonding: prevent potential infinite loop in bond_header_parse() Eric Dumazet
2026-03-14 12:03 ` Jiayuan Chen [this message]
2026-03-14 12:07   ` Eric Dumazet
2026-03-14 17:50 ` Jakub Kicinski
2026-03-14 17:59   ` Eric Dumazet
2026-03-15  3:42 ` kernel test robot

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