lkml.org 
[lkml]   [2003]   [Feb]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: [PATCH 3/8] dm: prevent possible buffer overflow in ioctl interface
Date
On Friday 28 February 2003 08:32, you wrote:
> On Thu, 2003-02-27 at 14:05, Kevin Corry wrote:
> > Unfortunately, Linus seems to have committed that patch already. So here
> > is a patch to fix just that line.
> >
> > Thanks for catching that.
>
> Third time, strlen isn't necessary, it can be done at compile time.
>
> --- a/drivers/md/dm-ioctl.c 2003/02/27 16:29:58
> +++ b/drivers/md/dm-ioctl.c 2003/02/27 17:21:54
> @@ -174,7 +174,7 @@
> static int register_with_devfs(struct hash_cell *hc)
> {
> struct gendisk *disk = dm_disk(hc->md);
> - char *name = kmalloc(DM_NAME_LEN + strlen(DM_DIR) + 1);
> + char *name = kmalloc(DM_NAME_LEN + sizeof(DM_DIR));
> if (!name) {
> return -ENOMEM;
> }

Sorry, I sent the last patch before I got your email.

Also, the "+1" is still necessary, even if we switch to sizeof. The sprintf
call that follows copies DM_DIR, followed by a slash, followed by the name
from the hash table into the allocated string. The "+1" is for the slash in
the middle. The terminating NULL character is accounted for in DM_NAME_LEN.

Linus, here is (yet another!) patch against current BK.

--
Kevin Corry
corryk@us.ibm.com
http://evms.sourceforge.net/


--- linux-2.5.63-bk4a/drivers/md/dm-ioctl.c Fri Feb 28 08:43:19 2003
+++ linux-2.5.63-bk4b/drivers/md/dm-ioctl.c Fri Feb 28 08:44:08 2003
@@ -174,7 +174,7 @@
static int register_with_devfs(struct hash_cell *hc)
{
struct gendisk *disk = dm_disk(hc->md);
- char *name = kmalloc(DM_NAME_LEN + strlen(DM_DIR) + 1, GFP_KERNEL);
+ char *name = kmalloc(DM_NAME_LEN + sizeof(DM_DIR) + 1, GFP_KERNEL);
if (!name) {
return -ENOMEM;
}
-
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 13:33    [W:0.037 / U:2.844 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site