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 received from userspace.
Therefore, the execution of the following branch if (sr_has_hmac(sr_phdr))
{ ... } will never complete since the len and type fields of a possible
HMAC TLV are not copied, hence seg6_get_tlv_hmac will return an error,
and the HMAC will not be computed.
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 <dleb...@google.com>
Signed-off-by: Mathieu Xhonneux <m.xhonn...@gmail.com>
---
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
