Messages in this thread |  | | Date | Wed, 10 Jan 2001 13:48:43 -0500 | From | Chris Mason <> | Subject | Re: [reiserfs-list] major security bug in reiserfs (may affect SuSE Linux) |
| |
On Wednesday, January 10, 2001 12:38:34 PM -0500 Alexander Viro <viro@math.psu.edu> wrote:
> On Wed, 10 Jan 2001, Chris Mason wrote: > >> In filldir, I don't like the line where we ((char *)dirent += reclen ; >> If reclen is much larger than the buffer sent from userspace, I don't >> see how we stay in bounds. > > So? copy_to_user() and put_user() will refuse to scramble the > kernel memory. IOW, dirent can be out of the userspace. Hell, user could > call getdents() and pass it a kernel pointer. Try it and you'll see what > happens. >
Ah thanks, that makes more sense. But, copy_to_user is only working on namelen bytes, and reclen is bigger than that. So, who is checking the value for the buf->current_dir pointer?
-chris
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
|  |