From 9ccff83b1322f95da7a74784cf6f47a481e03dc5 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Tue, 7 Mar 2023 16:31:27 -0500 Subject: [PATCH] netfilter: bridge: call pskb_may_pull in br_nf_check_hbh_len When checking Hop-by-hop option header, if the option data is in nonlinear area, it should do pskb_may_pull instead of discarding the skb as a bad IPv6 packet. Signed-off-by: Xin Long Reviewed-by: Simon Horman Acked-by: Nikolay Aleksandrov Reviewed-by: Aaron Conole Signed-off-by: Florian Westphal --- net/bridge/br_netfilter_ipv6.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/net/bridge/br_netfilter_ipv6.c b/net/bridge/br_netfilter_ipv6.c index 6b07f30..afd1c71 100644 --- a/net/bridge/br_netfilter_ipv6.c +++ b/net/bridge/br_netfilter_ipv6.c @@ -45,14 +45,18 @@ */ static int br_nf_check_hbh_len(struct sk_buff *skb) { - unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1); + int len, off = sizeof(struct ipv6hdr); + unsigned char *nh; u32 pkt_len; - const unsigned char *nh = skb_network_header(skb); - int off = raw - nh; - int len = (raw[1] + 1) << 3; - if ((raw + len) - skb->data > skb_headlen(skb)) + if (!pskb_may_pull(skb, off + 8)) goto bad; + nh = (unsigned char *)(ipv6_hdr(skb) + 1); + len = (nh[1] + 1) << 3; + + if (!pskb_may_pull(skb, off + len)) + goto bad; + nh = skb_network_header(skb); off += 2; len -= 2; -- 2.7.4