Re: [PATCH net] ipv6: sr: fix TLVs not being copied using setsockopt
From: Mathieu Xhonneux <hidden>
Date: 2018-01-07 16:55:24
Just realized I messed up the justification about sr_has_hmac. The branch will be taken, but its execution will not complete since the TLV's len and type fields aren't copied, hence seg6_get_tlv_hmac will fail, and the HMAC will not be computed. 2018-01-07 17:12 GMT+00:00 Mathieu Xhonneux [off-list ref]:
quoted hunk ↗ jump to hunk
Function ipv6_push_rthdr4 allows to add an IPv6 Segment Routing Header to a socket through setsockopt, but the current implementation doesn't copy possible TLVs at the end of the SRH (i.e., the following branch if (sr_has_hmac(sr_phdr)) will never be taken as no HMAC TLV is copied). This commit adds a memcpy in case TLVs have been appended to the SRH. Fixes: a149e7c7ce812561f0fdc7a86ddc42f294e5eb3e ("ipv6: sr: add support for SRH injection through setsockopt") Acked-by: David Lebrun <redacted> Signed-off-by: Mathieu Xhonneux <redacted> --- net/ipv6/exthdrs.c | 9 +++++++++ 1 file changed, 9 insertions(+)diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 83bd75713535..bc68eb661970 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c@@ -925,6 +925,15 @@ static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto, sr_phdr->segments[0] = **addr_p; *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left]; + if (sr_ihdr->hdrlen > hops * 2) { + int tlvs_offset, tlvs_length; + + tlvs_offset = (1 + hops * 2) << 3; + tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3; + memcpy((char *)sr_phdr + tlvs_offset, + (char *)sr_ihdr + tlvs_offset, tlvs_length); + } + #ifdef CONFIG_IPV6_SEG6_HMAC if (sr_has_hmac(sr_phdr)) { struct net *net = NULL; --2.15.1