On Thu, Jul 11, 2019 at 12:50:13PM -0700, Eric Biggers wrote: > Hi Mimi, > > On Thu, Jul 11, 2019 at 10:14:36AM -0400, Mimi Zohar wrote: > > Hi Eric, > > > > On Mon, 2019-06-03 at 09:35 -0700, syzbot wrote: > > > syzbot has found a reproducer for the following crash on: > > > > > > HEAD commit: 3c09c195 Add linux-next specific files for 20190531 > > > git tree: linux-next > > > console output: https://syzkaller.appspot.com/x/log.txt?x=10f61a0ea00000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=6cfb24468280cd5c > > > dashboard link: https://syzkaller.appspot.com/bug?extid=5ab61747675a87ea359d > > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=177c3d16a00000 > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14ec01baa00000 > > > > > > > This reproducer seems like it is similar, but the cause is different > > than the original report. One has to do with overlayfs, while the > > other has to do with ext4, mprotect/mmap. I assume in both cases an > > IMA policy was required to trigger the locking bug. What type of IMA > > policy are you using? > > > > Do we need to differentiate the two reports? Is the "last occurred" > > notification for the overlay, for mprotect, or both? Please Cc the > > overlay mailing list on the overlay aspect. > > AFAICS, syzbot boots all kernels with "ima_policy=tcb" on the command line. > And I don't think anything in userspace changes the IMA policy. > > It's not unusual for multiple underlying bugs to get mixed into the same syzbot > bug. syzbot doesn't know that one "possible deadlock in process_measurement" is > different from another. "Last occurred" is for any crash that appeared as such. > > This just needs to be handled the best we can. Sometimes all the bugs can be > fixed; sometimes they've already been fixed; or sometimes it's easiest to fix > just one and then mark the syzbot bug as fixed, and syzbot will report it again > it's still occurring for some other reason. > > - Eric Invalidating this bug report as per the discussion at https://lkml.kernel.org/linux-integrity/1563122888.4539.119.camel@xxxxxxxxxxxxx/T/#mcd083826e5843f048c914c56a4e82147fc211704 #syz invalid For future reference, anyone can update the status of syzbot bugs; no need to ask me to do it. See https://goo.gl/tpsmEJ#status - Eric
