On Fri, Dec 15, 2017 at 05:40:15PM +0100, Thomas Gleixner wrote: > On Thu, 14 Dec 2017, Eric Biggers wrote: > > On Thu, Dec 14, 2017 at 04:34:12PM +0100, Thomas Gleixner wrote: > > > On Thu, 14 Dec 2017, Dmitry Vyukov wrote: > > > > On Thu, Dec 14, 2017 at 3:26 PM, Thomas Gleixner <t...@linutronix.de> > > > > wrote: > > > > > On Tue, 12 Dec 2017, Greg KH wrote: > > > > >> Did this ever go anywhere? I don't see it in Linus's tree yet... > > > > > > > > > > I learned yesterday that syzboz is understuffed and cannot test > > > > > patches, so > > > > > I need to find a minute to run the reproducer myself and verify that > > > > > the > > > > > patch is correct. > > > > > > > > Hi Thomas, > > > > > > > > Why do you say so? Have you tried to ask it to test? > > > > https://github.com/google/syzkaller/blob/master/docs/syzbot.md#communication-with-syzbot > > > > What happened? > > > > > > Eric explained that to me yesterday and I did not try yet. > > > > > > > Your patch definitely fixes the bug (I tested the C reproducers, you just > > need > > to build a kernel with CONFIG_CHECKPOINT_RESTORE=y and > > CONFIG_POSIX_TIMERS=y, > > then run them). The real question is whether the check being introduced is > > too > > strict -- are there users passing in other values for ->sigev_notify that > > would > > be broken? That I can't really answer. > > Me neither. The manpage is rather clear about the possible values, so I > don't expect wreckage. Aside of that non canonical values would have to > have bit 2, i.e. SIGEV_THREAD_ID cleared because that already has a > restriction that it's only allowed with SIGEV_SIGNAL. So unlikely... > > If really some crap application breaks we can handle it in the default > clause by setting it to SIGEV_SIGNAL. Though I rather prefer not to do that > unless it turns out to be absolutely necessary. >
I see a fix is committed now (thanks!), so let's tell syzbot: #syz fix: posix-timer: Properly check sigevent->sigev_notify
