6.7-stable review patch. If anyone has any objections, please let me know.
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From: Justin Iurman justin.iurman@uliege.be
[ Upstream commit f198d933c2e4f8f89e0620fbaf1ea7eac384a0eb ]
ioam6_fill_trace_data() writes inside the skb payload without ensuring it's writeable (e.g., not cloned). This function is called both from the input and output path. The output path (ioam6_iptunnel) already does the check. This commit provides a fix for the input path, inside ipv6_hop_ioam(). It also updates ip6_parse_tlv() to refresh the network header pointer ("nh") when returning from ipv6_hop_ioam().
Fixes: 9ee11f0fff20 ("ipv6: ioam: Data plane support for Pre-allocated Trace") Reported-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Justin Iurman justin.iurman@uliege.be Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv6/exthdrs.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 4952ae7924505..02e9ffb63af19 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -177,6 +177,8 @@ static bool ip6_parse_tlv(bool hopbyhop, case IPV6_TLV_IOAM: if (!ipv6_hop_ioam(skb, off)) return false; + + nh = skb_network_header(skb); break; case IPV6_TLV_JUMBO: if (!ipv6_hop_jumbo(skb, off)) @@ -943,6 +945,14 @@ static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) if (!skb_valid_dst(skb)) ip6_route_input(skb);
+ /* About to mangle packet header */ + if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len)) + goto drop; + + /* Trace pointer may have changed */ + trace = (struct ioam6_trace_hdr *)(skb_network_header(skb) + + optoff + sizeof(*hdr)); + ioam6_fill_trace_data(skb, ns, trace, true); break; default: