summaryrefslogtreecommitdiff
path: root/include/net/dst_metadata.h
diff options
context:
space:
mode:
authorTaehee Yoo <ap420073@gmail.com>2021-07-09 17:35:18 +0000
committerDavid S. Miller <davem@davemloft.net>2021-07-09 13:55:53 -0700
commit67a9c94317402b826fc3db32afc8f39336803d97 (patch)
treeb9471c7c8c75e463ae157caccf4afa73c50a101e /include/net/dst_metadata.h
parent9992a078b1771da354ac1f9737e1e639b687caa2 (diff)
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.h4
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;