netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Daniel Borkmann <daniel@iogearbox.net>
To: alexei.starovoitov@gmail.com
Cc: netdev@vger.kernel.org, Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH bpf-next v3 07/11] bpf: make sure to clear unused fields in tunnel/xfrm state fetch
Date: Sat,  2 Jun 2018 23:06:37 +0200	[thread overview]
Message-ID: <20180602210641.6163-8-daniel@iogearbox.net> (raw)
In-Reply-To: <20180602210641.6163-1-daniel@iogearbox.net>

Since the remaining bits are not filled in struct bpf_tunnel_key
resp. struct bpf_xfrm_state and originate from uninitialized stack
space, we should make sure to clear them before handing control
back to the program.

Also add a padding element to struct bpf_xfrm_state for future use
similar as we have in struct bpf_tunnel_key and clear it as well.

  struct bpf_xfrm_state {
      __u32                      reqid;            /*     0     4 */
      __u32                      spi;              /*     4     4 */
      __u16                      family;           /*     8     2 */

      /* XXX 2 bytes hole, try to pack */

      union {
          __u32              remote_ipv4;          /*           4 */
          __u32              remote_ipv6[4];       /*          16 */
      };                                           /*    12    16 */

      /* size: 28, cachelines: 1, members: 4 */
      /* sum members: 26, holes: 1, sum holes: 2 */
      /* last cacheline: 28 bytes */
  };

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
---
 include/uapi/linux/bpf.h | 3 ++-
 net/core/filter.c        | 6 ++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 6613181..f0b6608 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2268,7 +2268,7 @@ struct bpf_tunnel_key {
 	};
 	__u8 tunnel_tos;
 	__u8 tunnel_ttl;
-	__u16 tunnel_ext;
+	__u16 tunnel_ext;	/* Padding, future use. */
 	__u32 tunnel_label;
 };
 
@@ -2279,6 +2279,7 @@ struct bpf_xfrm_state {
 	__u32 reqid;
 	__u32 spi;	/* Stored in network byte order */
 	__u16 family;
+	__u16 ext;	/* Padding, future use. */
 	union {
 		__u32 remote_ipv4;	/* Stored in network byte order */
 		__u32 remote_ipv6[4];	/* Stored in network byte order */
diff --git a/net/core/filter.c b/net/core/filter.c
index edbfaa6..28e8647 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3445,6 +3445,7 @@ BPF_CALL_4(bpf_skb_get_tunnel_key, struct sk_buff *, skb, struct bpf_tunnel_key
 	to->tunnel_id = be64_to_cpu(info->key.tun_id);
 	to->tunnel_tos = info->key.tos;
 	to->tunnel_ttl = info->key.ttl;
+	to->tunnel_ext = 0;
 
 	if (flags & BPF_F_TUNINFO_IPV6) {
 		memcpy(to->remote_ipv6, &info->key.u.ipv6.src,
@@ -3452,6 +3453,8 @@ BPF_CALL_4(bpf_skb_get_tunnel_key, struct sk_buff *, skb, struct bpf_tunnel_key
 		to->tunnel_label = be32_to_cpu(info->key.label);
 	} else {
 		to->remote_ipv4 = be32_to_cpu(info->key.u.ipv4.src);
+		memset(&to->remote_ipv6[1], 0, sizeof(__u32) * 3);
+		to->tunnel_label = 0;
 	}
 
 	if (unlikely(size != sizeof(struct bpf_tunnel_key)))
@@ -4047,11 +4050,14 @@ BPF_CALL_5(bpf_skb_get_xfrm_state, struct sk_buff *, skb, u32, index,
 	to->reqid = x->props.reqid;
 	to->spi = x->id.spi;
 	to->family = x->props.family;
+	to->ext = 0;
+
 	if (to->family == AF_INET6) {
 		memcpy(to->remote_ipv6, x->props.saddr.a6,
 		       sizeof(to->remote_ipv6));
 	} else {
 		to->remote_ipv4 = x->props.saddr.a4;
+		memset(&to->remote_ipv6[1], 0, sizeof(__u32) * 3);
 	}
 
 	return 0;
-- 
2.9.5

  parent reply	other threads:[~2018-06-02 21:07 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-02 21:06 [PATCH bpf-next v3 00/11] Misc BPF improvements Daniel Borkmann
2018-06-02 21:06 ` [PATCH bpf-next v3 01/11] bpf: test case for map pointer poison with calls/branches Daniel Borkmann
2018-06-02 21:06 ` [PATCH bpf-next v3 02/11] bpf: add also cbpf long jump test cases with heavy expansion Daniel Borkmann
2018-06-02 21:06 ` [PATCH bpf-next v3 03/11] bpf: fixup error message from gpl helpers on license mismatch Daniel Borkmann
2018-06-02 21:06 ` [PATCH bpf-next v3 04/11] bpf: show prog and map id in fdinfo Daniel Borkmann
2018-06-02 21:06 ` [PATCH bpf-next v3 05/11] bpf: avoid retpoline for lookup/update/delete calls on maps Daniel Borkmann
2018-06-03  6:56   ` Jesper Dangaard Brouer
2018-06-03 16:11     ` Daniel Borkmann
2018-06-03 17:08       ` Jesper Dangaard Brouer
2018-06-04 11:02         ` Phil Sutter
2018-06-04 18:25           ` Jakub Kicinski
2018-06-04 19:45             ` Daniel Borkmann
2018-06-04 22:36             ` David Ahern
2018-06-02 21:06 ` [PATCH bpf-next v3 06/11] bpf: add bpf_skb_cgroup_id helper Daniel Borkmann
2018-06-02 21:06 ` Daniel Borkmann [this message]
2018-06-02 21:06 ` [PATCH bpf-next v3 08/11] bpf: fix cbpf parser bug for octal numbers Daniel Borkmann
2018-06-02 21:06 ` [PATCH bpf-next v3 09/11] bpf: fix context access in tracing progs on 32 bit archs Daniel Borkmann
2018-06-02 21:06 ` [PATCH bpf-next v3 10/11] bpf: sync bpf uapi header with tools Daniel Borkmann
2018-06-02 21:06 ` [PATCH bpf-next v3 11/11] bpf, doc: add missing patchwork url and libbpf to maintainers Daniel Borkmann
2018-06-03 15:08 ` [PATCH bpf-next v3 00/11] Misc BPF improvements Alexei Starovoitov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180602210641.6163-8-daniel@iogearbox.net \
    --to=daniel@iogearbox.net \
    --cc=alexei.starovoitov@gmail.com \
    --cc=netdev@vger.kernel.org \
    --subject='Re: [PATCH bpf-next v3 07/11] bpf: make sure to clear unused fields in tunnel/xfrm state fetch' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).