On Sun, May 06, 2018 at 02:03:57PM +0900, Tetsuo Handa wrote: > > Since syzbot is hitting this error path inside mount() request, calling > panic() when something went wrong inside mount() request might be > overkill. We can recover without shutting down the system, can't we? We could add a full kernel-mode fsck which gets run before mount --- the question is how much complexity we want to add. If SELinux is enabled, then we have to check xattr consinsistency, etc., etc. > > I could mark this as a one-off invalid bug, but if syzkaller is going > > to be generating classes of corrupted file systems like this, and are > > going to be complaing about how this causes the kernel to crash, then > > we have a fundamental syzkaller BUG. > > > If we won't try to recover this case, this specific report would be > marked as "#syz invalid". I can do that for this specific case. Howevre, I'd rather not have to mark a large number of reports as invalid, if syz is going to produce a large number of such things. Which is why I'm raising the questihon --- is there any way we can make syz smart enough to not raise false positvies in this case? In the future I can see the repro attempting to actually do stuff with the mounted file system, which is why I want to put my foot down now before the only answer really is adding a kernel-mode fsck before the file system is allowed to be mounted. Root is always going to be able to crash the system. For example, suppose syzkaller creates a repros which opens /dev/mem and starts scribbling all over it. Would we be happy if it started creating large number of reports for that class of "bug"? - Ted
