diff options
| author | Taehee Yoo <ap420073@gmail.com> | 2021-07-09 17:35:18 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-07-09 13:55:53 -0700 |
| commit | 67a9c94317402b826fc3db32afc8f39336803d97 (patch) | |
| tree | b9471c7c8c75e463ae157caccf4afa73c50a101e /include/net/dst_metadata.h | |
| parent | 9992a078b1771da354ac1f9737e1e639b687caa2 (diff) | |
| download | lwn-67a9c94317402b826fc3db32afc8f39336803d97.tar.gz lwn-67a9c94317402b826fc3db32afc8f39336803d97.zip | |
net: validate lwtstate->data before returning from skb_tunnel_info()
skb_tunnel_info() returns pointer of lwtstate->data as ip_tunnel_info
type without validation. lwtstate->data can have various types such as
mpls_iptunnel_encap, etc and these are not compatible.
So skb_tunnel_info() should validate before returning that pointer.
Splat looks like:
BUG: KASAN: slab-out-of-bounds in vxlan_get_route+0x418/0x4b0 [vxlan]
Read of size 2 at addr ffff888106ec2698 by task ping/811
CPU: 1 PID: 811 Comm: ping Not tainted 5.13.0+ #1195
Call Trace:
dump_stack_lvl+0x56/0x7b
print_address_description.constprop.8.cold.13+0x13/0x2ee
? vxlan_get_route+0x418/0x4b0 [vxlan]
? vxlan_get_route+0x418/0x4b0 [vxlan]
kasan_report.cold.14+0x83/0xdf
? vxlan_get_route+0x418/0x4b0 [vxlan]
vxlan_get_route+0x418/0x4b0 [vxlan]
[ ... ]
vxlan_xmit_one+0x148b/0x32b0 [vxlan]
[ ... ]
vxlan_xmit+0x25c5/0x4780 [vxlan]
[ ... ]
dev_hard_start_xmit+0x1ae/0x6e0
__dev_queue_xmit+0x1f39/0x31a0
[ ... ]
neigh_xmit+0x2f9/0x940
mpls_xmit+0x911/0x1600 [mpls_iptunnel]
lwtunnel_xmit+0x18f/0x450
ip_finish_output2+0x867/0x2040
[ ... ]
Fixes: 61adedf3e3f1 ("route: move lwtunnel state to dst_entry")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/dst_metadata.h')
| -rw-r--r-- | include/net/dst_metadata.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/net/dst_metadata.h b/include/net/dst_metadata.h index 56cb3c38569a..14efa0ded75d 100644 --- a/include/net/dst_metadata.h +++ b/include/net/dst_metadata.h @@ -45,7 +45,9 @@ skb_tunnel_info(const struct sk_buff *skb) return &md_dst->u.tun_info; dst = skb_dst(skb); - if (dst && dst->lwtstate) + if (dst && dst->lwtstate && + (dst->lwtstate->type == LWTUNNEL_ENCAP_IP || + dst->lwtstate->type == LWTUNNEL_ENCAP_IP6)) return lwt_tun_info(dst->lwtstate); return NULL; |