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.
The problematic code is:
int devfs_mk_cdev(dev_t dev, umode_t mode, const char *fmt, ...)
{
struct devfs_entry *dir = NULL, *de;
char buf[64];
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;
}
One option would be to try to initialise buf earlier, another would be
to just remove the "for %s" part, and the buf reference in the printk
(but that way, some information would be lost).
Anyways, I just noticed that when my buggy code called devfs_mk_cdev
(blah, 0, etc..) it printed garbage on module insertion, so I thought
I'd drop a notice.
Oh, this is with Linux 2.6.0-test1-mm1.
Cheers,
-- Gergely Nagy - 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/
This archive was generated by hypermail 2b29 : Wed Jul 23 2003 - 22:00:27 EST