Messages in this thread | | | Subject | Re: [PATCH v2] Add kernel config option for fuzz testing. | From | Jiri Slaby <> | Date | Sat, 7 Mar 2020 17:28:22 +0100 |
| |
On 07. 03. 20, 14:58, Tetsuo Handa wrote: > While syzkaller is finding many bugs, sometimes syzkaller examines > stupid operations. Currently we prevent syzkaller from examining > stupid operations by blacklisting syscall arguments and/or disabling > whole functionality using existing kernel config options, but it is > a whack-a-mole approach. We need cooperation from kernel side [1]. > > This patch introduces a kernel config option which allows disabling > only specific operations. This kernel config option should be enabled > only when building kernels for fuzz testing. > > We discussed possibility of disabling specific operations at run-time > using some lockdown mechanism [2], but conclusion seems that build-time > control (i.e. kernel config option) fits better for this purpose. > Since patches for users of this kernel config option will want a lot of > explanation [3], this patch provides only kernel config option for them. > > [1] https://github.com/google/syzkaller/issues/1622 > [2] https://lkml.kernel.org/r/CACdnJutc7OQeoor6WLTh8as10da_CN=crs79v3Fp0mJTaO=+yw@mail.gmail.com > [3] https://lkml.kernel.org/r/20191216163155.GB2258618@kroah.com > > Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> > Cc: Dmitry Vyukov <dvyukov@google.com> > --- > lib/Kconfig.debug | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > Changes since v1: > Drop users of this kernel config option. > Update patch description. > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index 53e786e0a604..e360090e24c5 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -2208,4 +2208,14 @@ config HYPERV_TESTING > > endmenu # "Kernel Testing and Coverage" > > +config KERNEL_BUILT_FOR_FUZZ_TESTING > + bool "Build kernel for fuzz testing"
If we really want to go this way, I wouldn't limit it for fuzz testing only. Static analyzers, symbolic executors, formal verifiers, etc. -- all of them should avoid the paths.
So what about KERNEL_BUILT_FOR_ANALYZERS?
> + default n > + help > + Say N unless you are building kernels for fuzz testing. > + Saying Y here disables several things that legitimately cause > + damage under a fuzzer workload (e.g. copying to arbitrary > + user-specified kernel address, changing console loglevel, > + freezing filesystems). > + > endmenu # Kernel hacking >
-- js suse labs
| |