On Tue, Nov 17, 2015 at 12:34:44PM -0600, Seth Forshee wrote: > On Tue, Nov 17, 2015 at 05:55:06PM +0000, Al Viro wrote: > > On Tue, Nov 17, 2015 at 11:25:51AM -0600, Seth Forshee wrote: > > > > > Shortly after that I plan to follow with support for ext4. I've been > > > fuzzing ext4 for a while now and it has held up well, and I'm currently > > > working on hand-crafted attacks. Ted has commented privately (to others, > > > not to me personally) that he will fix bugs for such attacks, though I > > > haven't seen any public comments to that effect. > > > > _Static_ attacks, or change-image-under-mounted-fs attacks? > > Right now only static attacks, change-image-under-mounted-fs attacks > will be next. I will fix bugs about static attacks. That is, it's interesting to me that a buggy file system (no matter how it is created), not cause the kernel to crash --- and privilege escalation attacks tend to be strongly related to those bugs where we're not doing strong enough checking. Protecting against a malicious user which changes the image under the file system is a whole other kettle of fish. I am not at all user you can do this without completely sacrificing performance or making the code impossible to maintain. So my comments do *not* extend to protecting against a malicious user who is changing the block device underneath the kernel. If you want to submit patches to make the kernel more robust against these attacks, I'm certainly willing to look at the patches. But I'm certainly not guaranteeing that they will go in, and I'm certainly not promising to fix all vulnerabilities that you might find that are caused by a malicious block device. Sorry, that's too much buying a pig in a poke.... - Ted -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
