On 8/29/19 5:53 PM, Philippe Mathieu-Daudé wrote: > On 8/29/19 5:43 PM, Philippe Mathieu-Daudé wrote: >> On 8/26/19 12:54 AM, Samuel Thibault wrote: >>> Philippe Mathieu-Daudé, le ven. 23 août 2019 17:15:32 +0200, a ecrit: >>>>> Did you make your test with commit 126c04acbabd ("Fix heap overflow in >>>>> ip_reass on big packet input") applied? >>>> >>>> Yes, unfortunately it doesn't fix the issue. >>> >>> Ok. >>> >>> Could you try the attached patch? There was a use-after-free. Without >>> it, I can indeed crash qemu with the given exploit. With it I don't >>> seem to be able to crash it (trying in a loop for several minutes). > [...] >> >> Note 2: We miss some Makefile rules in QEMU with the libslirp split. >> >> Checkouting branches in the slirp/ directory doesn't trigger recompiling >> the slirp object, and even if I force the creation of the libslirp.a >> archive, the QEMU binaries are not linked again with the refreshed archive. > > And I hit the same issue after applying your patch =) > > So, using a clean workspace, I can not reproduce the null deref anymore. > > If you send a proper patch, feel free to add: > > Tested-by: Philippe Mathieu-Daudé <phi...@redhat.com>
I was going to suggest to also add: Reported-by: Quan Wenli <wq...@redhat.com> But you answered in another thread that this patch was already commited 3 days ago as: https://gitlab.freedesktop.org/slirp/libslirp/commit/d203c81b