From: Joonwoo Park <joonwpark81@gmail.com>
Date: Fri, 28 Mar 2008 23:27:33 +0000 (-0700)
Subject: [LLC]: bogus llc packet length
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=27785d83e4256fedeff45256d4c827fdcb47f2ce;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

[LLC]: bogus llc packet length

discard llc packet which has bogus packet length.

Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/llc/llc_input.c b/net/llc/llc_input.c
index c40c9b2a345a..bfd2567dd365 100644
--- a/net/llc/llc_input.c
+++ b/net/llc/llc_input.c
@@ -117,8 +117,12 @@ static inline int llc_fixup_skb(struct sk_buff *skb)
 	skb_pull(skb, llc_len);
 	if (skb->protocol == htons(ETH_P_802_2)) {
 		__be16 pdulen = eth_hdr(skb)->h_proto;
-		u16 data_size = ntohs(pdulen) - llc_len;
+		s32 data_size = ntohs(pdulen) - llc_len;
 
+		if (data_size < 0 ||
+		    ((skb_tail_pointer(skb) -
+		      (u8 *)pdu) - llc_len) < data_size)
+			return 0;
 		if (unlikely(pskb_trim_rcsum(skb, data_size)))
 			return 0;
 	}