mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-05 18:39:59 +00:00
net: validate untrusted gso packets without csum offload
commitd5be7f632b
upstream. Syzkaller again found a path to a kernel crash through bad gso input. By building an excessively large packet to cause an skb field to wrap. If VIRTIO_NET_HDR_F_NEEDS_CSUM was set this would have been dropped in skb_partial_csum_set. GSO packets that do not set checksum offload are suspicious and rare. Most callers of virtio_net_hdr_to_skb already pass them to skb_probe_transport_header. Move that test forward, change it to detect parse failure and drop packets on failure as those cleary are not one of the legitimate VIRTIO_NET_HDR_GSO types. Fixes:bfd5f4a3d6
("packet: Add GSO/csum offload support.") Fixes:f43798c276
("tun: Allow GSO using virtio_net_hdr") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
6964c1d506
commit
dac7d4432b
2 changed files with 10 additions and 1 deletions
|
@ -2377,7 +2377,7 @@ static inline void skb_probe_transport_header(struct sk_buff *skb,
|
|||
return;
|
||||
else if (skb_flow_dissect_flow_keys(skb, &keys, 0))
|
||||
skb_set_transport_header(skb, keys.control.thoff);
|
||||
else
|
||||
else if (offset_hint >= 0)
|
||||
skb_set_transport_header(skb, offset_hint);
|
||||
}
|
||||
|
||||
|
|
|
@ -57,6 +57,15 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
|
|||
|
||||
if (!skb_partial_csum_set(skb, start, off))
|
||||
return -EINVAL;
|
||||
} else {
|
||||
/* gso packets without NEEDS_CSUM do not set transport_offset.
|
||||
* probe and drop if does not match one of the above types.
|
||||
*/
|
||||
if (gso_type) {
|
||||
skb_probe_transport_header(skb, -1);
|
||||
if (!skb_transport_header_was_set(skb))
|
||||
return -EINVAL;
|
||||
}
|
||||
}
|
||||
|
||||
if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
|
||||
|
|
Loading…
Reference in a new issue