Commit 121d57af authored by Willem de Bruijn's avatar Willem de Bruijn Committed by David S. Miller

gso: validate gso_type in GSO handlers

Validate gso_type during segmentation as SKB_GSO_DODGY sources
may pass packets where the gso_type does not match the contents.

Syzkaller was able to enter the SCTP gso handler with a packet of
gso_type SKB_GSO_TCPV4.

On entry of transport layer gso handlers, verify that the gso_type
matches the transport protocol.

Fixes: 90017acc ("sctp: Add GSO support")
Link: http://lkml.kernel.org/r/<001a1137452496ffc305617e5fe0@google.com>
Reported-by: syzbot+fee64147a25aecd48055@syzkaller.appspotmail.com
Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Reviewed-by: default avatarMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7c68d1a6
......@@ -122,6 +122,9 @@ static struct sk_buff *esp4_gso_segment(struct sk_buff *skb,
if (!xo)
goto out;
if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
goto out;
seq = xo->seq.low;
x = skb->sp->xvec[skb->sp->len - 1];
......
......@@ -32,6 +32,9 @@ static void tcp_gso_tstamp(struct sk_buff *skb, unsigned int ts_seq,
static struct sk_buff *tcp4_gso_segment(struct sk_buff *skb,
netdev_features_t features)
{
if (!(skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4))
return ERR_PTR(-EINVAL);
if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
return ERR_PTR(-EINVAL);
......
......@@ -203,6 +203,9 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
goto out;
}
if (!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP))
goto out;
if (!pskb_may_pull(skb, sizeof(struct udphdr)))
goto out;
......
......@@ -149,6 +149,9 @@ static struct sk_buff *esp6_gso_segment(struct sk_buff *skb,
if (!xo)
goto out;
if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP))
goto out;
seq = xo->seq.low;
x = skb->sp->xvec[skb->sp->len - 1];
......
......@@ -46,6 +46,9 @@ static struct sk_buff *tcp6_gso_segment(struct sk_buff *skb,
{
struct tcphdr *th;
if (!(skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6))
return ERR_PTR(-EINVAL);
if (!pskb_may_pull(skb, sizeof(*th)))
return ERR_PTR(-EINVAL);
......
......@@ -42,6 +42,9 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
const struct ipv6hdr *ipv6h;
struct udphdr *uh;
if (!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP))
goto out;
if (!pskb_may_pull(skb, sizeof(struct udphdr)))
goto out;
......
......@@ -45,6 +45,9 @@ static struct sk_buff *sctp_gso_segment(struct sk_buff *skb,
struct sk_buff *segs = ERR_PTR(-EINVAL);
struct sctphdr *sh;
if (!(skb_shinfo(skb)->gso_type & SKB_GSO_SCTP))
goto out;
sh = sctp_hdr(skb);
if (!pskb_may_pull(skb, sizeof(*sh)))
goto out;
......
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