Linux-remoteproc Archive mirror
 help / color / mirror / Atom feed
From: Justin Stitt <justinstitt@google.com>
To: Bjorn Andersson <andersson@kernel.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-hardening@vger.kernel.org,
	Justin Stitt <justinstitt@google.com>
Subject: [PATCH] rpmsg: replace deprecated strncpy with strscpy_pad
Date: Fri, 20 Oct 2023 23:18:59 +0000	[thread overview]
Message-ID: <20231020-strncpy-drivers-rpmsg-rpmsg_ns-c-v1-1-99b16b00c36c@google.com> (raw)

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

We expect chinfo.name to be NUL-terminated based on its use with format
strings:
|       dev_err(&ctrldev->dev, "failed to create %s channel\n", chinfo.name);

Since chinfo is not default initialized, we should NUL-pad the `name`
field so that the behavior is consistent with what strncpy() provides:
|       struct rpmsg_channel_info chinfo;

Considering the above, a suitable replacement is `strscpy_pad` due to
the fact that it guarantees both NUL-termination and NUL-padding on the
destination buffer.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Note: build-tested only.

Found with: $ rg "strncpy\("
---
 drivers/rpmsg/rpmsg_ns.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c
index c70ad03ff2e9..bde8c8d433e0 100644
--- a/drivers/rpmsg/rpmsg_ns.c
+++ b/drivers/rpmsg/rpmsg_ns.c
@@ -50,7 +50,7 @@ static int rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len,
 	/* don't trust the remote processor for null terminating the name */
 	msg->name[RPMSG_NAME_SIZE - 1] = '\0';
 
-	strncpy(chinfo.name, msg->name, sizeof(chinfo.name));
+	strscpy_pad(chinfo.name, msg->name, sizeof(chinfo.name));
 	chinfo.src = RPMSG_ADDR_ANY;
 	chinfo.dst = rpmsg32_to_cpu(rpdev, msg->addr);
 

---
base-commit: 9c5d00cb7b6bbc5a7965d9ab7d223b5402d1f02c
change-id: 20231020-strncpy-drivers-rpmsg-rpmsg_ns-c-ffe3fa2bb9ff

Best regards,
--
Justin Stitt <justinstitt@google.com>


                 reply	other threads:[~2023-10-20 23:19 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=20231020-strncpy-drivers-rpmsg-rpmsg_ns-c-v1-1-99b16b00c36c@google.com \
    --to=justinstitt@google.com \
    --cc=andersson@kernel.org \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-remoteproc@vger.kernel.org \
    --cc=mathieu.poirier@linaro.org \
    /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 read-only IMAP folder(s) and NNTP newsgroup(s).