netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Kees Cook <keescook@chromium.org>
To: "David S. Miller" <davem@davemloft.net>
Cc: Kees Cook <keescook@chromium.org>,
	Jakub Kicinski <kuba@kernel.org>,
	Justin Iurman <justin.iurman@uliege.be>,
	Eric Dumazet <edumazet@google.com>,
	Paolo Abeni <pabeni@redhat.com>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-hardening@vger.kernel.org
Subject: [PATCH] ipv6: ioam: Replace 0-length array with flexible array
Date: Thu,  5 Jan 2023 14:21:16 -0800	[thread overview]
Message-ID: <20230105222115.never.661-kees@kernel.org> (raw)

Zero-length arrays are deprecated[1]. Replace struct ioam6_trace_hdr's
"data" 0-length array with a flexible array. Detected with GCC 13,
using -fstrict-flex-arrays=3:

net/ipv6/ioam6_iptunnel.c: In function 'ioam6_build_state':
net/ipv6/ioam6_iptunnel.c:194:37: warning: array subscript <unknown> is outside array bounds of '__u8[0]' {aka 'unsigned char[]'} [-Warray-bounds=]
  194 |                 tuninfo->traceh.data[trace->remlen * 4] = IPV6_TLV_PADN;
      |                 ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~
In file included from include/linux/ioam6.h:11,
                 from net/ipv6/ioam6_iptunnel.c:13:
include/uapi/linux/ioam6.h:130:17: note: while referencing 'data'
  130 |         __u8    data[0];
      |                 ^~~~

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Justin Iurman <justin.iurman@uliege.be>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/uapi/linux/ioam6.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/uapi/linux/ioam6.h b/include/uapi/linux/ioam6.h
index ac4de376f0ce..8f72b24fefb3 100644
--- a/include/uapi/linux/ioam6.h
+++ b/include/uapi/linux/ioam6.h
@@ -127,7 +127,7 @@ struct ioam6_trace_hdr {
 #endif
 
 #define IOAM6_TRACE_DATA_SIZE_MAX 244
-	__u8	data[0];
+	__u8	data[];
 } __attribute__((packed));
 
 #endif /* _UAPI_LINUX_IOAM6_H */
-- 
2.34.1


             reply	other threads:[~2023-01-05 22:21 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-05 22:21 Kees Cook [this message]
2023-01-06 16:03 ` [PATCH] ipv6: ioam: Replace 0-length array with flexible array Gustavo A. R. Silva
2023-01-06 20:22 ` Justin Iurman
2023-01-07  3:40 ` patchwork-bot+netdevbpf

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=20230105222115.never.661-kees@kernel.org \
    --to=keescook@chromium.org \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=gustavoars@kernel.org \
    --cc=justin.iurman@uliege.be \
    --cc=kuba@kernel.org \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
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).