On 7/24/23 08:47, Richard W.M. Jones wrote: > On Sun, Jul 23, 2023 at 11:18:45PM -0400, Demi Marie Obenour wrote: >> On 7/23/23 12:10, Solomon Peachy via devel wrote: >>> On Sun, Jul 23, 2023 at 11:25:12AM -0400, Neal Gompa wrote: >>>>> If the system administrator wants to mount $UNCOMMONFS, they should be >>>>> able to do so without hassle, but that doesn't mean that a normal user >>>>> who got handed a sketchy USB stick at a conference should be able to do >>>>> so with no restrictions at all. >>>>> >>>> >>>> So then some kind of configuration to udisks2 to have a similar effect? >>> >>> And we're right back at square one, with the *overwhelmingly* common case >>> of a single-user system whose "admin" is sitting in front of the system. >>> >>> Of _course_ they want to mount the disk. It's why they plugged it in, >>> and they don't give two hoots if it's a "common filesystem" or not. >>> >>> (FFS, most of the stuff I personally plug in these days is ext4 or ntfs, >>> because fat32 sucks and I can't rely on exfat on all systems I need to >>> interoperate with) >>> >>> And let's be realistic here -- the overwhelmingly common threat model >>> here is that there are untrusted files on a correctly-formed filesystem. >>> Bad guys rarely need or care to get root on the system; what they're >>> after requires normal, non-elevated user permissions. >>> >>> Prompting users 'are you sure you want to use this device' will turn a >>> "yes" into an automatic reflex. Not automounting by default will just >>> add another thing to the "things to change on default fedora >>> installations" lists out there (ie right after the "enable freshrpms and >>> install modern video codecs" step), becuase it's a usability nightmare. >>> >>> In the "usability vs security" tradeoff, usability/convenience *always* >>> wins unless you're at a place that has armed guards at the door with >>> instructions to shoot first. >>> >>> - Solomon >> >> Then the mount needs to be done in a sandbox, such as a KVM guest or >> sandboxed userspace process. > > This is what libguestfs does (KVM guest). > > Rich. I saw that libguestfs has a guestmount(1) tool, and I think this could be a potential solution. An exploit against the kernel FS driver would only grant access to a KVM guest, and the QEMU process can be tightly sandboxed by means such as seccomp and SELinux. I still believe that mounting should _not_ be automatic, though, because it could have side-effects (such as replaying the FS journal) that might not be wanted. To prevent prompt fatigue, Fedora could offer to remember the user’s choice. -- Sincerely, Demi Marie Obenour (she/her/hers) _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
