From: Azeem Shaikh <azeemshaikh38@gmail.com>
To: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-hardening@vger.kernel.org, linux-scsi@vger.kernel.org,
target-devel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] scsi: target: Replace strlcpy with strscpy
Date: Wed, 30 Aug 2023 16:11:34 -0400 [thread overview]
Message-ID: <CADmuW3Wfryaj7gGLQhVwJm4eWbEoaQ50k_BwgEWfO+ETKWkNvA@mail.gmail.com> (raw)
In-Reply-To: <20230830200717.4129442-1-azeemshaikh38@gmail.com>
Please ignore this patch. There are more strlcpy()->strscpy()
replacement in the same file that did not get included here. Will send
out a v2 with all the changes to make it easier for reviewers.
On Wed, Aug 30, 2023 at 4:07 PM Azeem Shaikh <azeemshaikh38@gmail.com> wrote:
>
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
>
> Direct replacement is safe here since return value of -errno
> is used to check for truncation instead of sizeof(dest).
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
>
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
> ---
> drivers/target/target_core_configfs.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
> index 936e5ff1b209..b3d2c14e2ea9 100644
> --- a/drivers/target/target_core_configfs.c
> +++ b/drivers/target/target_core_configfs.c
> @@ -1392,16 +1392,15 @@ static ssize_t target_wwn_vendor_id_store(struct config_item *item,
> /* +2 to allow for a trailing (stripped) '\n' and null-terminator */
> unsigned char buf[INQUIRY_VENDOR_LEN + 2];
> char *stripped = NULL;
> - size_t len;
> + ssize_t len;
> ssize_t ret;
>
> - len = strlcpy(buf, page, sizeof(buf));
> - if (len < sizeof(buf)) {
> + len = strscpy(buf, page, sizeof(buf));
> + if (len > 0) {
> /* Strip any newline added from userspace. */
> stripped = strstrip(buf);
> - len = strlen(stripped);
> }
> - if (len > INQUIRY_VENDOR_LEN) {
> + if (len < 0 || strlen(stripped) > INQUIRY_VENDOR_LEN) {
> pr_err("Emulated T10 Vendor Identification exceeds"
> " INQUIRY_VENDOR_LEN: " __stringify(INQUIRY_VENDOR_LEN)
> "\n");
> --
> 2.42.0.283.g2d96d420d3-goog
>
>
prev parent reply other threads:[~2023-08-30 21:04 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-30 20:07 [PATCH] scsi: target: Replace strlcpy with strscpy Azeem Shaikh
2023-08-30 20:11 ` Azeem Shaikh [this message]
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