lkml.org 
[lkml]   [2003]   [Jul]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [devfs] Use before initialisation in devfs_mk_cdev()
On Thu, Jul 17, 2003 at 01:53:42AM +0200, Gergely Nagy wrote:
> Hi!
>
> While playing around with implementing my first linux 2.5 module, I
> stumbled upon a buglet in devfs (though, if used properly, it probably
> won't surface ever). The problem - as I see it - is that
> devfs_mk_cdev() first checks the mode passed to it, and if it thinks
> it is not a char device, it prints a warning and aborts. Now, this
> printing involves the local variable `buf' (char buf[64]), which is
> not initialised at that point.

Sorry, my fault. I had a report on this earlier but didn't submit
a patch yet. The same problem also affects devfs_mk_bdev.

Linus, please apply the patch below.


--- 1.95/fs/devfs/base.c Fri Jul 11 01:24:00 2003
+++ edited/fs/devfs/base.c Fri Jul 18 11:36:24 2003
@@ -1432,12 +1432,6 @@
va_list args;
int error, n;

- if (!S_ISBLK(mode)) {
- printk(KERN_WARNING "%s: invalide mode (%u) for %s\n",
- __FUNCTION__, mode, buf);
- return -EINVAL;
- }
-
va_start(args, fmt);
n = vsnprintf(buf, 64, fmt, args);
if (n >= 64 || !buf[0]) {
@@ -1445,6 +1439,12 @@
__FUNCTION__);
return -EINVAL;
}
+
+ if (!S_ISBLK(mode)) {
+ printk(KERN_WARNING "%s: invalide mode (%u) for %s\n",
+ __FUNCTION__, mode, buf);
+ return -EINVAL;
+ }

de = _devfs_prepare_leaf(&dir, buf, mode);
if (!de) {
@@ -1478,17 +1478,17 @@
va_list args;
int error, n;

- if (!S_ISCHR(mode)) {
- printk(KERN_WARNING "%s: invalide mode (%u) for %s\n",
- __FUNCTION__, mode, buf);
- return -EINVAL;
- }
-
va_start(args, fmt);
n = vsnprintf(buf, 64, fmt, args);
if (n >= 64 || !buf[0]) {
printk(KERN_WARNING "%s: invalid format string\n",
__FUNCTION__);
+ return -EINVAL;
+ }
+
+ if (!S_ISCHR(mode)) {
+ printk(KERN_WARNING "%s: invalide mode (%u) for %s\n",
+ __FUNCTION__, mode, buf);
return -EINVAL;
}

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2005-03-22 13:46    [W:0.032 / U:0.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site