br_nd_send() walks ND options according to option-provided lengths.
A malformed option can make the parser advance beyond the computed
option span or use a too-short source LLADDR option payload.
Validate option lengths against the remaining NS option area before
advancing, and only read source LLADDR when the option is large enough
for an Ethernet address.
Fixes: ed842faeb2bd ("bridge: suppress nd pkts on BR_NEIGH_SUPPRESS ports")
Cc: [email protected]
Reported-by: Yifan Wu <[email protected]>
Reported-by: Juefei Pu <[email protected]>
Tested-by: Ao Zhou <[email protected]>
Co-developed-by: Yuan Tan <[email protected]>
Signed-off-by: Yuan Tan <[email protected]>
Suggested-by: Xin Liu <[email protected]>
Signed-off-by: Yang Yang <[email protected]>
---
net/bridge/br_arp_nd_proxy.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c
index af3d1e33f50b8..6b5595868a39c 100644
--- a/net/bridge/br_arp_nd_proxy.c
+++ b/net/bridge/br_arp_nd_proxy.c
@@ -288,12 +288,14 @@ static void br_nd_send(struct net_bridge *br, struct
net_bridge_port *p,
ns_olen = request->len - (skb_network_offset(request) +
sizeof(struct ipv6hdr)) - sizeof(*ns);
for (i = 0; i < ns_olen - 1; i += (ns->opt[i + 1] << 3)) {
- if (!ns->opt[i + 1]) {
+ if (!ns->opt[i + 1] || i + (ns->opt[i + 1] << 3) > ns_olen) {
kfree_skb(reply);
return;
}
if (ns->opt[i] == ND_OPT_SOURCE_LL_ADDR) {
- daddr = ns->opt + i + sizeof(struct nd_opt_hdr);
+ if ((ns->opt[i + 1] << 3) >=
+ sizeof(struct nd_opt_hdr) + ETH_ALEN)
+ daddr = ns->opt + i + sizeof(struct nd_opt_hdr);
break;
}
}
--
2.43.0
