On Wed, May 23, 2018 at 8:01 PM, Eric Sandeen <sandeen@xxxxxxxxxxx> wrote: > On 5/23/18 11:20 AM, Eric Biggers wrote: > > ... > > > I'd revise that to "have to fix /some/ of them anyway." > > What I'm personally hung up on are the bugs where the "exploit" involves > merely > mounting a crafted filesystem that in reality would never (until the heat > death > of the universe) corrupt itself into that state on its own; it's the > "malicious > image" case, which is quite different than exposing fundamental bugs like > the > SB_BORN race or or the user-exploitable ext4 flaw you mentioned in your > reply. > Those are more insidious and/or things which can be hit by real users in > real life. > > I don't know if I can win the "malicious images aren't a critical security > threat" battle, but I do think they are at least a different class of flaws, > because as Dave said, mount is supposed to be a privileged operation. > In a perfect world we'd fix them anyway, but I don't know that our resource > pool can keep up with your google-scale bot and still make progress in other > critical areas. > > Anyway, the upshot is that we're probably just not going to care much about > V4 > filesystem oops-or-hang-on-mount bugs. Those problems are solved (largely) > with > V5 filesystem format. Maybe I /will/ propose a system-wide tunable to > disallow > V4 for those who are worried about such things. > > To Darrick's points about more collaboration, I still wish that our requests > for more traditional fs fuzzer reporting (i.e. a filesystem image) weren't > met > with such resistance.Tailoring your bug reports to the needs of the > developer > community you're interacting with seems like a pretty reasonable thing to > do. > > As an aside, I wonder how much coverage of the V5 format code syzkaller > /has/ > achieved; that would be another useful datapoint google could provide - if > syzkaller is in fact traversing the V5 codepaths and isn't turning anything > up, that'd be pretty useful to know. Hi Eric, The current syzbot kernel code coverage is available here: https://storage.googleapis.com/syzkaller/cover/upstream.html#9c73bb525fc1def86e67f5039ab97d8f48062621 -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
