Messages in this thread | | | Date | Thu, 26 Apr 2001 22:06:06 +0200 | From | Andrea Arcangeli <> | Subject | Re: [PATCH] SMP race in ext2 - metadata corruption. |
| |
On Thu, Apr 26, 2001 at 03:17:54PM -0400, Alexander Viro wrote: > > > On Thu, 26 Apr 2001, I wrote: > > > On Thu, 26 Apr 2001, Linus Torvalds wrote: > > > > > I see the race, but I don't see how you can actually trigger it. > > > > > > Exactly _who_ does the "read from device" part? Somebody doing a > > > "fsck" while the filesystem is mounted read-write and actively written > > > to? Yeah, you'd get disk corruption that way, but you'll get it regardless > > > of this bug. > > OK, I think I've a better explanation now: > > Suppose /dev/hda1 is owned by root.disks and permissions are 640. > It is mounted read-write. > > Process foo belongs to pfy.staff. PFY is included into disks, but doesn't > have root. I claim that he should be unable to cause fs corruption on > /dev/hda1. > > Currently foo _can_ cause such corruption, even though it has nothing > resembling write permissions for device in question. > > IMO it is wrong. I'm not saying that it's a real security problem. I'm > not saying that PFY is not idiot or that his actions make any sense. > However, I think that situation when he can do that without write > access to device is just plain wrong. > > Does the above make sense?
Sure. And as said `dump` has the same issues.
Andrea - 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/
| |