net: fix use-after-free in GRO with ESP

Since the addition of GRO for ESP, gro_receive can consume the skb and
return -EINPROGRESS. In that case, the lower layer GRO handler cannot
touch the skb anymore.

Commit 5f114163f2 ("net: Add a skb_gro_flush_final helper.") converted
some of the gro_receive handlers that can lead to ESP's gro_receive so
that they wouldn't access the skb when -EINPROGRESS is returned, but
missed other spots, mainly in tunneling protocols.

This patch finishes the conversion to using skb_gro_flush_final(), and
adds a new helper, skb_gro_flush_final_remcsum(), used in VXLAN and
GUE.

Fixes: 5f114163f2 ("net: Add a skb_gro_flush_final helper.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Sabrina Dubroca 2018-06-30 17:38:55 +02:00 committed by David S. Miller
parent 1236f22fba
commit 603d4cf8fe
7 changed files with 26 additions and 10 deletions

View File

@ -476,7 +476,7 @@ static struct sk_buff **geneve_gro_receive(struct sock *sk,
out_unlock:
rcu_read_unlock();
out:
NAPI_GRO_CB(skb)->flush |= flush;
skb_gro_flush_final(skb, pp, flush);
return pp;
}

View File

@ -623,9 +623,7 @@ static struct sk_buff **vxlan_gro_receive(struct sock *sk,
flush = 0;
out:
skb_gro_remcsum_cleanup(skb, &grc);
skb->remcsum_offload = 0;
NAPI_GRO_CB(skb)->flush |= flush;
skb_gro_flush_final_remcsum(skb, pp, flush, &grc);
return pp;
}

View File

@ -2789,11 +2789,31 @@ static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff **pp,
if (PTR_ERR(pp) != -EINPROGRESS)
NAPI_GRO_CB(skb)->flush |= flush;
}
static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
struct sk_buff **pp,
int flush,
struct gro_remcsum *grc)
{
if (PTR_ERR(pp) != -EINPROGRESS) {
NAPI_GRO_CB(skb)->flush |= flush;
skb_gro_remcsum_cleanup(skb, grc);
skb->remcsum_offload = 0;
}
}
#else
static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff **pp, int flush)
{
NAPI_GRO_CB(skb)->flush |= flush;
}
static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
struct sk_buff **pp,
int flush,
struct gro_remcsum *grc)
{
NAPI_GRO_CB(skb)->flush |= flush;
skb_gro_remcsum_cleanup(skb, grc);
skb->remcsum_offload = 0;
}
#endif
static inline int dev_hard_header(struct sk_buff *skb, struct net_device *dev,

View File

@ -693,7 +693,7 @@ static struct sk_buff **vlan_gro_receive(struct sk_buff **head,
out_unlock:
rcu_read_unlock();
out:
NAPI_GRO_CB(skb)->flush |= flush;
skb_gro_flush_final(skb, pp, flush);
return pp;
}

View File

@ -448,9 +448,7 @@ next_proto:
out_unlock:
rcu_read_unlock();
out:
NAPI_GRO_CB(skb)->flush |= flush;
skb_gro_remcsum_cleanup(skb, &grc);
skb->remcsum_offload = 0;
skb_gro_flush_final_remcsum(skb, pp, flush, &grc);
return pp;
}

View File

@ -223,7 +223,7 @@ static struct sk_buff **gre_gro_receive(struct sk_buff **head,
out_unlock:
rcu_read_unlock();
out:
NAPI_GRO_CB(skb)->flush |= flush;
skb_gro_flush_final(skb, pp, flush);
return pp;
}

View File

@ -394,7 +394,7 @@ unflush:
out_unlock:
rcu_read_unlock();
out:
NAPI_GRO_CB(skb)->flush |= flush;
skb_gro_flush_final(skb, pp, flush);
return pp;
}
EXPORT_SYMBOL(udp_gro_receive);