On Fri, 15 Jan 2016 15:38:58 +0100, Dmitry Vyukov wrote: > > On Fri, Jan 15, 2016 at 2:51 PM, Takashi Iwai <tiwai@xxxxxxx> wrote: > > On Fri, 15 Jan 2016 12:03:17 +0100, > > Dmitry Vyukov wrote: > >> > >> On Fri, Jan 15, 2016 at 12:00 PM, Takashi Iwai <tiwai@xxxxxxx> wrote: > >> > On Fri, 15 Jan 2016 09:06:10 +0100, > >> > Dmitry Vyukov wrote: > >> >> > >> >> On Thu, Jan 14, 2016 at 5:09 PM, Takashi Iwai <tiwai@xxxxxxx> wrote: > >> >> > On Wed, 13 Jan 2016 21:54:10 +0100, > >> >> > Takashi Iwai wrote: > >> >> >> > >> >> >> OK, then this might be a possible race at the current snd_timer_stop() > >> >> >> implementation. There is no sync action there, so the ISR might be > >> >> >> still alive after snd_timer_close() call. Or might be another race. > >> >> >> This pattern looks a bit different, as it's involved with hrtimer. > >> >> >> > >> >> >> I'll take a look at it tomorrow. > >> >> > > >> >> > I've audited the code today, but the open window doesn't look like > >> >> > what I expected. I found only some possible cases with slave timer > >> >> > instances. > >> >> > > >> >> > In anyway, below is a test fix patch. Since I couldn't reproduce the > >> >> > issue on my local machines, it's hard to say whether this covers the > >> >> > holes you fell. Let's see... > >> >> > >> >> > >> >> Hi Takashi, > >> >> > >> >> I would be interested to understand why other people can't reproduce > >> >> issues that I hit pretty reliably. > >> >> I suspect that it can be due to .config. Please try with the following > >> >> config values. > >> > > >> > I guess rather other config, e.g. the kernel debug options. > >> > I suppose you enabled KASAN and DEBUG_LIST. What else? > >> > >> I've attached my config (you will need to disable CONFIG_KCOV, it is > >> not upstreamed). > > > > Hm, that has lots of other drivers built-in... > > > >> >> I also start qemu with "-soundhw all" arg. > >> > > >> > OK, so you're testing with VM? This makes easier to recheck. > >> > >> Yes, I start qemu as: > >> > >> qemu-system-x86_64 -hda wheezy.img -net > >> user,host=10.0.2.10,hostfwd=tcp::10022-:22 -net nic -nographic -kernel > >> arch/x86/boot/bzImage -append "console=ttyS0 root=/dev/sda debug > >> earlyprintk=serial slub_debug=UZ" -enable-kvm -m 2G -numa > >> node,nodeid=0,cpus=0-1 -numa node,nodeid=1,cpus=2-3 -smp > >> sockets=2,cores=2,threads=1 -usb -usbdevice mouse -usbdevice tablet > >> -soundhw all > > > > And which test did trigger use-after-free, even with all previous > > patches? > > I will try to extract a new reproducer now. > Meanwhile, can you try to reproduce this one: > https://groups.google.com/forum/#!msg/syzkaller/bbtG9_h1ONU/CPLblMC6FAAJ > ? I run the program in a tight parallel loop. So you're running this in parallel? Or a tight sequential loop? I did the latter, and I tried even this on a bare metal, but couldn't trigger the Oops, so far. Meanwhile, I pushed the tree including all fixes at for-linus branch: git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git for-linus It'd be appreciated if you can test this one. thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
