linux-hardening - [PATCH] accessibility: speakup: refactor deprecated strncpy

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 24 Aug 2023 21:44:29 +0000
From:   Justin Stitt <justinstitt@...gle.com>
To:     William Hubbs <w.d.hubbs@...il.com>,
        Chris Brannon <chris@...-brannons.com>,
        Kirk Reiser <kirk@...sers.ca>,
        Samuel Thibault <samuel.thibault@...-lyon.org>
Cc:     speakup@...ux-speakup.org, linux-kernel@...r.kernel.org,
        linux-hardening@...r.kernel.org,
        Justin Stitt <justinstitt@...gle.com>
Subject: [PATCH] accessibility: speakup: refactor deprecated strncpy

`strncpy` is deprecated for use on NUL-terminated destination strings [1].

Use `strscpy` as it guarantees NUL-termination of its destination buffer [2]
which allows for simpler and less ambiguous code.

Also, change `strlen(buf)` to `strlen(ptr)` to be consistent with
further usage within the scope of the function. Note that these are
equivalent:
|419 	const char *ptr = buf;

Link: 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@...r.kernel.org
Signed-off-by: Justin Stitt <justinstitt@...gle.com>
---
Note: build-tested only.
---
 drivers/accessibility/speakup/kobjects.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/accessibility/speakup/kobjects.c b/drivers/accessibility/speakup/kobjects.c
index a7522d409802..8aa416c5f3fc 100644
--- a/drivers/accessibility/speakup/kobjects.c
+++ b/drivers/accessibility/speakup/kobjects.c
@@ -422,12 +422,11 @@ static ssize_t synth_direct_store(struct kobject *kobj,
 	if (!synth)
 		return -EPERM;
 
-	len = strlen(buf);
+	len = strlen(ptr);
 	spin_lock_irqsave(&speakup_info.spinlock, flags);
 	while (len > 0) {
 		bytes = min_t(size_t, len, 250);
-		strncpy(tmp, ptr, bytes);
-		tmp[bytes] = '\0';
+		strscpy(tmp, ptr, bytes);
 		string_unescape_any_inplace(tmp);
 		synth_printf("%s", tmp);
 		ptr += bytes;

---
base-commit: f9604036a3fb6149badf346994b46b03f9292db7
change-id: 20230824-strncpy-drivers-accessibility-speakup-kobjects-c-4009e7df0936

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