linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Justin Stitt <justinstitt@google.com>
To: Tyrel Datwyler <tyreld@linux.ibm.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	 Nicholas Piggin <npiggin@gmail.com>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	 "James E.J. Bottomley" <jejb@linux.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Justin Stitt <justinstitt@google.com>,
	linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
	linux-scsi@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH] scsi: ibmvscsi: replace deprecated strncpy with strscpy
Date: Mon, 30 Oct 2023 20:40:48 +0000	[thread overview]
Message-ID: <20231030-strncpy-drivers-scsi-ibmvscsi-ibmvscsi-c-v1-1-f8b06ae9e3d5@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 partition_name to be NUL-terminated based on its usage with
format strings:
|       dev_info(hostdata->dev, "host srp version: %s, "
|                "host partition %s (%d), OS %d, max io %u\n",
|                hostdata->madapter_info.srp_version,
|                hostdata->madapter_info.partition_name,
|                be32_to_cpu(hostdata->madapter_info.partition_number),
|                be32_to_cpu(hostdata->madapter_info.os_type),
|                be32_to_cpu(hostdata->madapter_info.port_max_txu[0]));
...
|       len = snprintf(buf, PAGE_SIZE, "%s\n",
|                hostdata->madapter_info.partition_name);

Moreover, NUL-padding is not required as madapter_info is explicitly
memset to 0:
|       memset(&hostdata->madapter_info, 0x00,
|                       sizeof(hostdata->madapter_info));

Considering the above, a suitable replacement is `strscpy` [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
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/scsi/ibmvscsi/ibmvscsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 59599299615d..71f3e9563520 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -266,7 +266,7 @@ static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
 	dev_info(hostdata->dev, "SRP_VERSION: %s\n", SRP_VERSION);
 	strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
 
-	strncpy(hostdata->madapter_info.partition_name, partition_name,
+	strscpy(hostdata->madapter_info.partition_name, partition_name,
 			sizeof(hostdata->madapter_info.partition_name));
 
 	hostdata->madapter_info.partition_number =

---
base-commit: ffc253263a1375a65fa6c9f62a893e9767fbebfa
change-id: 20231030-strncpy-drivers-scsi-ibmvscsi-ibmvscsi-c-3b5019ce50ad

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


             reply	other threads:[~2023-10-30 20:41 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-30 20:40 Justin Stitt [this message]
2023-11-30 21:13 ` [PATCH] scsi: ibmvscsi: replace deprecated strncpy with strscpy Kees Cook
2023-12-01  9:41 ` Michael Ellerman
2023-12-06  1:58   ` Martin K. Petersen
2023-12-14  4:29 ` Martin K. Petersen

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=20231030-strncpy-drivers-scsi-ibmvscsi-ibmvscsi-c-v1-1-f8b06ae9e3d5@google.com \
    --to=justinstitt@google.com \
    --cc=christophe.leroy@csgroup.eu \
    --cc=jejb@linux.ibm.com \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=martin.petersen@oracle.com \
    --cc=mpe@ellerman.id.au \
    --cc=npiggin@gmail.com \
    --cc=tyreld@linux.ibm.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).