syzkaller reproducers

[Dmitry Vyukov]

Hi Shuah,

We discussed collecting and uploading all syzkaller reproducers
somewhere. You wanted to see how they look. I've uploaded all current
reproducers here:
https://github.com/dvyukov/syzkaller-repros
Minimalistic build/run scripts are included.
+some testing mailing lists too as this can be used as a test suite
If you have any potential uses for this, you are welcome to use it.
But then we probably need to find some more official and shared place
for them than my private github.
The test programs can also be bulk updated if necessary, because all
of this is auto-generated.

Thanks

[Dmitry Vyukov]

+more people who expressed interest in the test suite before

[Richard Palethorpe]

Hello,

I discussed this a bit with Metan. We think it would be fairly trivial
to create an LTP wrapper for these.

So we just create an LTP test which forks and execs one of these
reproducers then checks for kernel taints after the child completes or
is killed. It can take the reproducer path as an argument and we can
generate a runtest file with all the reproducers in that we are able to
compile.

I imagine a lot of these reproducers will not work on older kernels, so
this would just be a best efforts basis. We would ignore any problems
during execution unless there is a kernel error.

This should work with existing LTP runners with maybe a minor change or
two to building and configuration.

I will start experimenting with this and post the results to the LTP
mailing list.

--
Thank you,
Richard.

[Dmitry Vyukov]

Hi Richard,

Sounds great!

Yes, these are totally best effort. May also require some configs, etc.
Also note that each should be run in a clean temp dir and with a
timeout b/c some have an infinite loop.

[Richard Palethorpe]

Thanks, fortunately the LTP lib can do that automatically.

However the default timeout is 5 minutes, but I guess this should be
more like ~3 seconds as in the run script?

--
Thank you,
Richard.

[Dmitry Vyukov]

This really depends on the bug type and specific bug.
syzkaller runs reproducers for up to 7 minutes. Sometimes even that is
not enough to reproduce some bugs. We also detect hung tasks only
after 3-4 minutes (may produce flakes with smaller timeout).
Most reproducers can also run in parallel, that may help to partially
neutralize large timeouts.
But also if these run repeatedly/continuously, we can use smaller
timeout on each run (don't need to catch crash on every run).
Let's start with somewhere, we can tune later as we gather experience.

[shuah]

Thanks for putting this together. I am going to create a repo on
kernel.org t host these and pull your private git content in.

I will work on it this week and set things up.

thanks,
-- Shuah

[George Kennedy]

Thank you for putting this together Dmitry,

George

[Cyril Hrubis]

Hi!

> We discussed collecting and uploading all syzkaller reproducers
> somewhere. You wanted to see how they look. I've uploaded all current
> reproducers here:
> https://github.com/dvyukov/syzkaller-repros
> Minimalistic build/run scripts are included.

What is the reason behind statically linking the reproducers?

The difference between static and dynamic binary is a bit less than 4MB,
which gives difference of several gigabytes for the whole repo. This
amount of binary data would complicate and slow down any CI
significantly...

--
Cyril Hrubis
chr...@suse.cz

[Dmitry Vyukov]

Simply being able to run programs on a different machine. Dynamic
binaries generally don't run on a different linux machine. If you can
build dynamic binaries so that they run on test machine, feel free to
drop -static.

[shuah]

Playing with the git getting ready to host it on kernel.org git repo.
Build worked fine and I can't get the run.sh to work.

I expected it to run what is in

syzkaller-repros/bin

It doesn't seem to do that. Looks like it wants to build. Here is what
I see. What am I doing wrong? I did a build which worked. There are some
errors due to sys/cdefs.h missing.

++ for f in *
+++ pwd
++ bin=/mnt/data/lkml/syzkaller-repros/bin
+++ mktemp -d
++ dir=/tmp/tmp.S8CjM8muRj
++ cd /tmp/tmp.S8CjM8muRj
++ timeout -s KILL 3 /mnt/data/lkml/syzkaller-repros/bin
timeout: failed to run command ‘/mnt/data/lkml/syzkaller-repros/bin’:
Permission denied
++ rm -rf /tmp/tmp.S8CjM8muRj
++ for f in *
+++ pwd
++ bin=/mnt/data/lkml/syzkaller-repros/build.sh
+++ mktemp -d
++ dir=/tmp/tmp.zAVygWdpkt
++ cd /tmp/tmp.zAVygWdpkt
++ timeout -s KILL 3 /mnt/data/lkml/syzkaller-repros/build.sh
linux/*.c
grep: linux/*.c: No such file or directory
gcc: error: linux/*.c: No such file or directory
gcc: fatal error: no input files
compilation terminated.
++ rm -rf /tmp/tmp.zAVygWdpkt
++ for f in *
+++ pwd
++ bin=/mnt/data/lkml/syzkaller-repros/LICENSE
+++ mktemp -d
++ dir=/tmp/tmp.hhcvgOc8RA
++ cd /tmp/tmp.hhcvgOc8RA
++ timeout -s KILL 3 /mnt/data/lkml/syzkaller-repros/LICENSE
timeout: failed to run command
‘/mnt/data/lkml/syzkaller-repros/LICENSE’: Permission denied
++ rm -rf /tmp/tmp.hhcvgOc8RA
++ for f in *
+++ pwd
++ bin=/mnt/data/lkml/syzkaller-repros/linux
+++ mktemp -d
++ dir=/tmp/tmp.sM5UO7BHRB
++ cd /tmp/tmp.sM5UO7BHRB
++ timeout -s KILL 3 /mnt/data/lkml/syzkaller-repros/linux
timeout: failed to run command ‘/mnt/data/lkml/syzkaller-repros/linux’:
Permission denied
++ rm -rf /tmp/tmp.sM5UO7BHRB
++ for f in *
+++ pwd
++ bin=/mnt/data/lkml/syzkaller-repros/README.md
+++ mktemp -d
++ dir=/tmp/tmp.4Kkrs6iLP5
++ cd /tmp/tmp.4Kkrs6iLP5
++ timeout -s KILL 3 /mnt/data/lkml/syzkaller-repros/README.md
timeout: failed to run command
‘/mnt/data/lkml/syzkaller-repros/README.md’: Permission denied
++ rm -rf /tmp/tmp.4Kkrs6iLP5
++ for f in *
+++ pwd
++ bin=/mnt/data/lkml/syzkaller-repros/run.sh
+++ mktemp -d
++ dir=/tmp/tmp.YFx5WEOvJn
++ cd /tmp/tmp.YFx5WEOvJn
++ timeout -s KILL 3 /mnt/data/lkml/syzkaller-repros/run.sh
+ pwd
+ bin=/tmp/tmp.YFx5WEOvJn/*
+ mktemp -d
+ dir=/tmp/tmp.qD4i4g9qYR
+ cd /tmp/tmp.qD4i4g9qYR
+ timeout -s KILL 3 /tmp/tmp.YFx5WEOvJn/*
timeout: failed to run command ‘/tmp/tmp.YFx5WEOvJn/*’: No such file or
directory
+ rm -rf /tmp/tmp.qD4i4g9qYR
++ rm -rf /tmp/tmp.YFx5WEOvJn

thanks,
-- Shuah

[Cyril Hrubis]

Hi!

> Playing with the git getting ready to host it on kernel.org git repo.
> Build worked fine and I can't get the run.sh to work.
>
> I expected it to run what is in
>
> syzkaller-repros/bin
>
> It doesn't seem to do that. Looks like it wants to build. Here is what
> I see. What am I doing wrong?

You are suposed to run the run.sh script in the bin directory.

> I did a build which worked. There are some errors due to sys/cdefs.h
> missing.

That is because you are missing 32bit gcc and devel libs.

--
Cyril Hrubis
chr...@suse.cz

[shuah]

On 10/11/19 12:02 PM, Cyril Hrubis wrote:
> Hi!
>> Playing with the git getting ready to host it on kernel.org git repo.
>> Build worked fine and I can't get the run.sh to work.
>>
>> I expected it to run what is in
>>
>> syzkaller-repros/bin
>>
>> It doesn't seem to do that. Looks like it wants to build. Here is what
>> I see. What am I doing wrong?
>
> You are suposed to run the run.sh script in the bin directory.

Yeah that does work.

Would be helpful to have usage instructions instead of failing. :)

>
>> I did a build which worked. There are some errors due to sys/cdefs.h
>> missing.
>
> That is because you are missing 32bit gcc and devel libs.
>

Yeah. I didn't think about that.

thanks,
-- Shuah

[Cyril Hrubis]

Hi!

> > You are suposed to run the run.sh script in the bin directory.
>
> Yeah that does work.
>
> Would be helpful to have usage instructions instead of failing. :)

I do not think that these scripts are ever supposed to be the used in
production testing, you need much more than this to produce results
reliably. I would expect that they are supposed to be a form of very
minimal documentation.

--
Cyril Hrubis
chr...@suse.cz

[Dmitry Vyukov]

Yes, I just added them as quick hints: some repros are 32-bits; each
needs a new dir; some external timeout is needed for each test.

[George Kennedy]

Thank you again for the collection of repro C programs!

Hitting a lot more crashes with the collection of repro C programs than
in all the hours of running Syzkaller. Wonder why? Any idea? This is
with the same kernel and VM that Syzkaller is run on.

George

[Cyril Hrubis]

Hi!

> >> I do not think that these scripts are ever supposed to be the used in
> >> production testing, you need much more than this to produce results
> >> reliably. I would expect that they are supposed to be a form of very
> >> minimal documentation.
> > Yes, I just added them as quick hints: some repros are 32-bits; each
> > needs a new dir; some external timeout is needed for each test.
> Thank you again for the collection of repro C programs!
>
> Hitting a lot more crashes with the collection of repro C programs than
> in all the hours of running Syzkaller. Wonder why? Any idea? This is
> with the same kernel and VM that Syzkaller is run on.

I would guess that these reproducers are product of countless hours of
fuzzing, so it's about to be expected...

--
Cyril Hrubis
chr...@suse.cz

[Dmitry Vyukov]

Probably. Hard to say.
If you used KCOV, KCOV_ENABLE_COMPARISONS, KASAN, LOCKDEP,
FAULT_INJECTION, all other debugging configs, compat instance and some
required image/cmdline features, then the only reason for difference
that I see is indeed longer fuzzing time.

[George Kennedy]

Hello Dmitry,

Could we get another drop of the Syzkaller C reproducers?

Wonder if we could get the drop periodically (i.e. a drop/quarter or a
drop to match a major linux release)?

Thank you,
George

[George Kennedy]

Hi Dmitry,

Re-sending this request.

Also, how do you track the Upstream branches with Syzkaller? Do you have
a version of Syzkaller for each (i.e. 4.14, 4.19, etc)?

Thank you,
George

[Dmitry Vyukov]

Hi George,

This was still starred in my inbox, but I never got to actually do
anything with it. Thanks for pinging me. I thought that the script to
extract the repros won't work for some reason and that I will need to
fix it first. But turns out it's still working as-is (I wanted to
submit some changes that would break it, but I never go to that as
well. Good! :)).

So here is a new drop in with 692 repros:
https://github.com/dvyukov/syzkaller-repros/commit/6a06992209c328a3115c89c020f45b844b103573
Enjoy!

Yes, we have separate managers for each version, the entries in the
Instances table correspond to syz-manager one-to-one:
https://syzkaller.appspot.com/upstream
https://syzkaller.appspot.com/linux-4.19
https://syzkaller.appspot.com/android-54

[George Kennedy]

On 1/27/2020 10:26 AM, Dmitry Vyukov wrote:
> Hi George,
>
> This was still starred in my inbox, but I never got to actually do
> anything with it. Thanks for pinging me. I thought that the script to
> extract the repros won't work for some reason and that I will need to
> fix it first. But turns out it's still working as-is (I wanted to
> submit some changes that would break it, but I never go to that as
> well. Good! :)).
>
> So here is a new drop in with 692 repros:
> https://github.com/dvyukov/syzkaller-repros/commit/6a06992209c328a3115c89c020f45b844b103573
> Enjoy!
>
> Yes, we have separate managers for each version, the entries in the
> Instances table correspond to syz-manager one-to-one:
> https://syzkaller.appspot.com/upstream
> https://syzkaller.appspot.com/linux-4.19
> https://syzkaller.appspot.com/android-54

Thank you Dmitry!
George

[Dmitry Vyukov]

Shauh,

We've added more reproducers to:
https://github.com/dvyukov/syzkaller-repros/tree/master/linux

It makes sense to pull in them to the kernel-arts repo. Not sure
what's the most convenient way for you since it's not exactly a
traditional "patch"? Perhaps you just copy linux/*.c files and commit?

George, another throw in of 446 repros ;)



On Mon, Jan 27, 2020 at 6:08 PM George Kennedy

[George Kennedy]

On 3/3/2020 3:45 AM, Dmitry Vyukov wrote:
> Shauh,
>
> We've added more reproducers to:
> https://github.com/dvyukov/syzkaller-repros/tree/master/linux
>
> It makes sense to pull in them to the kernel-arts repo. Not sure
> what's the most convenient way for you since it's not exactly a
> traditional "patch"? Perhaps you just copy linux/*.c files and commit?
>
> George, another throw in of 446 repros ;)

[shuah]

On 3/3/20 1:45 AM, Dmitry Vyukov wrote:
> Shauh,
>
> We've added more reproducers to:
> https://github.com/dvyukov/syzkaller-repros/tree/master/linux
>
> It makes sense to pull in them to the kernel-arts repo. Not sure
> what's the most convenient way for you since it's not exactly a
> traditional "patch"? Perhaps you just copy linux/*.c files and commit?
>

Thanks Dmitry. I will pull these in. I will pull these in.

thanks,
-- Shuah

[Dmitry Vyukov]

On Fri, Nov 20, 2020 at 3:16 PM George Kennedy
<george....@oracle.com> wrote:
>
> Hi Dmitry,
>
> Is there a new batch of repros available?

Here we go:
https://github.com/dvyukov/syzkaller-repros/commits/master

> Thank you,
> George
>
> On 7/13/2020 10:44 AM, George Kennedy wrote:
> > Hi Dmitry,
> >
> > Will there be a new batch of repros coming out anytime soon?
> >
> > Wish list item: it would be cool if there was a link off syzbot for
> > the repro repository. As repros are acknowledged as valid, they get
> > added to the repro.
> >
> > Thank you,
> > George

[George Kennedy]

On 11/21/2020 12:07 PM, Dmitry Vyukov wrote:
> On Fri, Nov 20, 2020 at 3:16 PM George Kennedy
> <george....@oracle.com> wrote:
>> Hi Dmitry,
>>
>> Is there a new batch of repros available?
> Here we go:
> https://github.com/dvyukov/syzkaller-repros/commits/master

Thank you Dmitry!

George

[Palash]

Hello all,

Reviving this old thread. Do we think there's value in automatically publishing a C reproducer(if it exists) whenever syzkaller determines a reported bug is patched and fixed?

This allows us to track these reproducers more diligently and we only have reproducers for the bugs that have been patched.

If this is valuable, then we could think about answering these questions -

1. Is there a particular way we want to format the reproducers? (Example : SKIP/OK/FAIL/TIMEOUT (if output is possible))

2. Where do we want to submit the reproducers to be added to the testing project and what is the process we want to use?

3. Is it valuable to record the crash report information for the original fuzzer crash when the c reproducer is filed to add context to it; in case developers want to troubleshoot? This could save valuable debugging time.

Happy to contribute on this change to the upstream fuzzing system.

Thanks,

Palash

[Dmitry Vyukov]

On Fri, 13 May 2022 at 02:54, Palash Oswal <oswal...@gmail.com> wrote:
>
> + Shuah, George and mailing lists
>
> Google groups did not CC all of the members in the thread for my
> reply. It would be valuable to get everyone's feedback on this thread.

>
> On Sat, May 7, 2022 at 11:34 PM Palash <oswal...@gmail.com> wrote:
> >
> > Hello all,
> >
> > Reviving this old thread. Do we think there's value in automatically publishing a C reproducer(if it exists) whenever syzkaller determines a reported bug is patched and fixed?
> > This allows us to track these reproducers more diligently and we only have reproducers for the bugs that have been patched.
> > If this is valuable, then we could think about answering these questions -
> > 1. Is there a particular way we want to format the reproducers? (Example : SKIP/OK/FAIL/TIMEOUT (if output is possible))
> > 2. Where do we want to submit the reproducers to be added to the testing project and what is the process we want to use?
> > 3. Is it valuable to record the crash report information for the original fuzzer crash when the c reproducer is filed to add context to it; in case developers want to troubleshoot? This could save valuable debugging time.
> >
> > Happy to contribute on this change to the upstream fuzzing system.

More automation is definitely welcome.
I am not sure how widely used is the current base of reproducers. But
George keeps asking for updates and I keep failing at doing it in a
timely manner.

It would be easiest for the syzbot app to upload reproducers to a GCS
bucket. But I am not sure what's a good format for this. Everything I
can think of is somewhat clumsy. It could upload weekly archives, but
then there is an issue of discoverability of new archives (since GCS
is HTTP rather than FTP).

Not sure if it's feasible to give it an auth token for a github repo
to push individual files as we do now.

Re format. Bonus points if the system will be able to regenerate and
update meta-information. The chances that we will come up with the
ultimately right format from day 1 are low. But that may complicate
the implementation.

> > Thanks,
> > Palash
> > On Friday, March 13, 2020 at 11:59:31 AM UTC-4 shuah wrote:
> >>
> >> On 3/3/20 1:45 AM, Dmitry Vyukov wrote:
> >> > Shauh,
> >> >
> >> > We've added more reproducers to:
> >> > https://github.com/dvyukov/syzkaller-repros/tree/master/linux
> >> >
> >> > It makes sense to pull in them to the kernel-arts repo. Not sure
> >> > what's the most convenient way for you since it's not exactly a
> >> > traditional "patch"? Perhaps you just copy linux/*.c files and commit?
> >> >
> >>
> >> Thanks Dmitry. I will pull these in. I will pull these in.
> >>
> >> thanks,
> >> -- Shuah
> >

> > --
> > You received this message because you are subscribed to a topic in the Google Groups "syzkaller" group.
> > To unsubscribe from this topic, visit https://groups.google.com/d/topic/syzkaller/RQFLqAvdsEc/unsubscribe.
> > To unsubscribe from this group and all its topics, send an email to syzkaller+...@googlegroups.com.
> > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller/cd301033-f152-4eeb-bce3-2d95f39a05fbn%40googlegroups.com.
>
>
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[Palash Oswal]

+ Shuah, George and mailing lists

Google groups did not CC all of the members in the thread for my
reply. It would be valuable to get everyone's feedback on this thread.

On Sat, May 7, 2022 at 11:34 PM Palash <oswal...@gmail.com> wrote:
>

[Dmitry Vyukov]

On Fri, 13 May 2022 at 13:35, George Kennedy <george....@oracle.com> wrote:
> >> + Shuah, George and mailing lists
> >>
> >> Google groups did not CC all of the members in the thread for my
> >> reply. It would be valuable to get everyone's feedback on this thread.
> >>
> >> On Sat, May 7, 2022 at 11:34 PM Palash <oswal...@gmail.com> wrote:
> >>> Hello all,
> >>>
> >>> Reviving this old thread. Do we think there's value in automatically publishing a C reproducer(if it exists) whenever syzkaller determines a reported bug is patched and fixed?
> >>> This allows us to track these reproducers more diligently and we only have reproducers for the bugs that have been patched.
> >>> If this is valuable, then we could think about answering these questions -
> >>> 1. Is there a particular way we want to format the reproducers? (Example : SKIP/OK/FAIL/TIMEOUT (if output is possible))
> >>> 2. Where do we want to submit the reproducers to be added to the testing project and what is the process we want to use?
> >>> 3. Is it valuable to record the crash report information for the original fuzzer crash when the c reproducer is filed to add context to it; in case developers want to troubleshoot? This could save valuable debugging time.
> >>>
> >>> Happy to contribute on this change to the upstream fuzzing system.
> >
> > More automation is definitely welcome.
> > I am not sure how widely used is the current base of reproducers. But
> > George keeps asking for updates and I keep failing at doing it in a
> > timely manner.

> We run the ~6000 reproducers as a regression test. Test takes ~4 hours.
>
> Having the reproducer before there is a patch is valuable to us as we
> know whether or not our distro branches have the same failure.
>
> As a way to reduce test time, some sort of repro classification would be
> helpful (i.e. open/closed/invalid).
>
> For crash troubleshooting info we try to match the crash string with
> syzbot's crash string.
>
> Thank you,
> George

> >
> > It would be easiest for the syzbot app to upload reproducers to a GCS
> > bucket. But I am not sure what's a good format for this. Everything I
> > can think of is somewhat clumsy. It could upload weekly archives, but
> > then there is an issue of discoverability of new archives (since GCS
> > is HTTP rather than FTP).
> >
> > Not sure if it's feasible to give it an auth token for a github repo
> > to push individual files as we do now.
> >
> > Re format. Bonus points if the system will be able to regenerate and
> > update meta-information. The chances that we will come up with the
> > ultimately right format from day 1 are low. But that may complicate
> > the implementation.

The most feasible for syzbot automation seems to be to push to a
public GCS bucket and then users will need to do "gsutil rsync" to
download updates.

Or another option is to expose a new json API to get reproducers list
and then to fetch individual reproducers. Though this will need some
custom tooling on the user side to fetch updates.

Re exporting status open/closed/invalid and e.g. fixing patch, that
would also be more natural to expose via the API since this
information changes dynamically.

It's also possible to use both. Namely, reproducers are uploaded to
the GCS bucket and each repro file contains just some bug ID. Then the
bug ID can be used to fetch any additional dynamically changing info
via json API.

[George Kennedy]

On 5/13/2022 5:29 AM, Dmitry Vyukov wrote:
> On Fri, 13 May 2022 at 02:54, Palash Oswal <oswal...@gmail.com> wrote:
>> + Shuah, George and mailing lists
>>
>> Google groups did not CC all of the members in the thread for my
>> reply. It would be valuable to get everyone's feedback on this thread.
>>
>> On Sat, May 7, 2022 at 11:34 PM Palash <oswal...@gmail.com> wrote:
>>> Hello all,
>>>
>>> Reviving this old thread. Do we think there's value in automatically publishing a C reproducer(if it exists) whenever syzkaller determines a reported bug is patched and fixed?
>>> This allows us to track these reproducers more diligently and we only have reproducers for the bugs that have been patched.
>>> If this is valuable, then we could think about answering these questions -
>>> 1. Is there a particular way we want to format the reproducers? (Example : SKIP/OK/FAIL/TIMEOUT (if output is possible))
>>> 2. Where do we want to submit the reproducers to be added to the testing project and what is the process we want to use?
>>> 3. Is it valuable to record the crash report information for the original fuzzer crash when the c reproducer is filed to add context to it; in case developers want to troubleshoot? This could save valuable debugging time.
>>>
>>> Happy to contribute on this change to the upstream fuzzing system.
>
> More automation is definitely welcome.
> I am not sure how widely used is the current base of reproducers. But
> George keeps asking for updates and I keep failing at doing it in a
> timely manner.

We run the ~6000 reproducers as a regression test. Test takes ~4 hours.

Having the reproducer before there is a patch is valuable to us as we
know whether or not our distro branches have the same failure.

As a way to reduce test time, some sort of repro classification would be
helpful (i.e. open/closed/invalid).

For crash troubleshooting info we try to match the crash string with
syzbot's crash string.

Thank you,
George
>

[Dmitry Vyukov]

I've pushed a new drop of 898 reproducers:
https://github.com/dvyukov/syzkaller-repros/commit/026c8891a19e672bba71481be250080e1a302ed8

[George Kennedy]

Thank you,
George

[Dmitry Vyukov]

On Mon, 16 May 2022 at 18:51, Shuah Khan <sk...@linuxfoundation.org> wrote:

> Thank you. I will update the linux-arts repo with this drop

Thank you!

[Shuah Khan]

Thank you. I will update the linux-arts repo with this drop

thanks,
-- Shuah

[George Kennedy]

Hi Dmitry,

Wondering if there is another batch of syzbot reproducers available?

Last batch I think was from May.

Thank you,
George

[Palash Oswal]

Here's a Python Script that I use for some regression testing research
that can download "fixed" syzkaller "C" reproducers from the
dashboard.
mkdir files
python3 script -
https://gist.github.com/oswalpalash/0502dc35f3ef32381ca2ae66e413a73a
Hope it is useful!

Thanks

[George Kennedy]

Thank you Palash,

Will try it out.

George