Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Alexei Starovoitov says:

====================
pull-request: bpf 2022-04-06

We've added 8 non-merge commits during the last 8 day(s) which contain
a total of 9 files changed, 139 insertions(+), 36 deletions(-).

The main changes are:

1) rethook related fixes, from Jiri and Masami.

2) Fix the case when tracing bpf prog is attached to struct_ops, from Martin.

3) Support dual-stack sockets in bpf_tcp_check_syncookie, from Maxim.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Adjust bpf_tcp_check_syncookie selftest to test dual-stack sockets
  bpf: Support dual-stack sockets in bpf_tcp_check_syncookie
  bpf: selftests: Test fentry tracing a struct_ops program
  bpf: Resolve to prog->aux->dst_prog->type only for BPF_PROG_TYPE_EXT
  rethook: Fix to use WRITE_ONCE() for rethook:: Handler
  selftests/bpf: Fix warning comparing pointer to 0
  bpf: Fix sparse warnings in kprobe_multi_resolve_syms
  bpftool: Explicit errno handling in skeletons
====================

Link: https://lore.kernel.org/r/20220407031245.73026-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 13 insertions, 4 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index a7044e98765e..64470a727ef7 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -7016,24 +7016,33 @@ BPF_CALL_5(bpf_tcp_check_syncookie, struct sock *, sk, void *, iph, u32, iph_len
 	if (!th->ack || th->rst || th->syn)
 		return -ENOENT;
 
+	if (unlikely(iph_len < sizeof(struct iphdr)))
+		return -EINVAL;
+
 	if (tcp_synq_no_recent_overflow(sk))
 		return -ENOENT;
 
 	cookie = ntohl(th->ack_seq) - 1;
 
-	switch (sk->sk_family) {
-	case AF_INET:
-		if (unlikely(iph_len < sizeof(struct iphdr)))
+	/* Both struct iphdr and struct ipv6hdr have the version field at the
+	 * same offset so we can cast to the shorter header (struct iphdr).
+	 */
+	switch (((struct iphdr *)iph)->version) {
+	case 4:
+		if (sk->sk_family == AF_INET6 && ipv6_only_sock(sk))
 			return -EINVAL;
 
 		ret = __cookie_v4_check((struct iphdr *)iph, th, cookie);
 		break;
 
 #if IS_BUILTIN(CONFIG_IPV6)
-	case AF_INET6:
+	case 6:
 		if (unlikely(iph_len < sizeof(struct ipv6hdr)))
 			return -EINVAL;
 
+		if (sk->sk_family != AF_INET6)
+			return -EINVAL;
+
 		ret = __cookie_v6_check((struct ipv6hdr *)iph, th, cookie);
 		break;
 #endif /* CONFIG_IPV6 */