accessibility: speakup: refactor deprecated strncpy

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

Let's refactor this function to just use synth_write().

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@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/20230918-strncpy-drivers-accessibility-speakup-kobjects-c-v2-1-d5b1976c5dbf@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Justin Stitt 2023-09-18 05:30:15 +00:00 committed by Greg Kroah-Hartman
parent 2953fa0306
commit 19e3e6cdfd

View file

@ -413,27 +413,24 @@ static ssize_t synth_direct_store(struct kobject *kobj,
struct kobj_attribute *attr, struct kobj_attribute *attr,
const char *buf, size_t count) const char *buf, size_t count)
{ {
u_char tmp[256]; char *unescaped;
int len;
int bytes;
const char *ptr = buf;
unsigned long flags; unsigned long flags;
if (!synth) if (!synth)
return -EPERM; return -EPERM;
len = strlen(buf); unescaped = kstrdup(buf, GFP_KERNEL);
if (!unescaped)
return -ENOMEM;
string_unescape_any_inplace(unescaped);
spin_lock_irqsave(&speakup_info.spinlock, flags); spin_lock_irqsave(&speakup_info.spinlock, flags);
while (len > 0) { synth_write(unescaped, strlen(unescaped));
bytes = min_t(size_t, len, 250);
strncpy(tmp, ptr, bytes);
tmp[bytes] = '\0';
string_unescape_any_inplace(tmp);
synth_printf("%s", tmp);
ptr += bytes;
len -= bytes;
}
spin_unlock_irqrestore(&speakup_info.spinlock, flags); spin_unlock_irqrestore(&speakup_info.spinlock, flags);
kfree(unescaped);
return count; return count;
} }