Re: syzkaller test panic: Linux 5.4.y

[john.p.donnelly@xxxxxxxxxx]

On 10/19/21 4:35 PM, Marcelo Ricardo Leitner wrote:
> On Tue, Oct 19, 2021 at 03:05:24PM -0500, john.p.donnelly@xxxxxxxxxx wrote:
> > On 10/19/21 10:24 AM, mleitner@xxxxxxxxxx wrote:
> > > Hi John,
> > >
> > > On Mon, Oct 18, 2021 at 04:29:58PM -0500, john.p.donnelly@xxxxxxxxxx wrote:
> > > >     Call Trace:
> > > >      skb_put+0x4c/0x4c
> > > >      sctp_addto_chunk+0x59/0xb0 [sctp]
> > > >      sctp_make_strreset_req+0x166/0x180 [sctp]
> > > >      sctp_send_reset_streams+0x14d/0x300 [sctp]
> > > >      sctp_setsockopt.part.21+0x101f/0x1720 [sctp]
> > > >      sctp_setsockopt+0x99/0xb0 [sctp]
> > > >      sock_common_setsockopt+0x1a/0x1c
> > > >      SyS_setsockopt+0x86/0xe6
> > > >      +0x79/0x1ae
> > > >      entry_SYSCALL_64_after_hwframe+0x151/0x0
> > > >    RIP: 0033:0x7f80bdc21be9
> > > >
> > > >
> > > > I am not familar with any of the sctp subsystem. It was found running the
> > > > syzkaller fuzzing test suite.
> > > >
> > > > If there is a more appropriate place to report this I can do that too. This
> > >
> > > Here is fine :)
> > >
> > > > test fails on just about every 4.x and 5.x kernel.  It is not
> > > > unique to 5.4.
> > >
> > > Did the test kernels include commit "sctp: account stream padding
> > > length for reconf chunk"? It is a recent fix right on this topic. It
> > > should be fixed by it, actually.
> > >
> > >     Marcelo
> >
> >
> > Hi Marcelo
> >
> >   I can confirm
> >
> >
> > commit a2d859e3fc97e79d907761550dbc03ff1b36479c
> > Author: Eiichi Tsukata <eiichi.tsukata@xxxxxxxxxxx>
> > Date:   Wed Oct 13 17:27:29 2021 -0300
> >
> >      sctp: account stream padding length for reconf chunk
> >
> > resolves my panic for 5.4.LTS   wrt to
> >
> > // autogenerated by syzkaller (https://urldefense.com/v3/__https://github.com/google/syzkaller__;!!ACWV5N9M2RV99hQ!bYZk3duFK90mfRvslAzHqUwzeJ2ngHYB0GMAZN3BITINKgzfZfAd5w8W5_OXRmoc_wDB$ )
> > //  317ef02b0d5cbd19d445294fed91453c7f970fc3.c
>
> Sweet!
>
> > Should be an easy enough fix to apply to older 4.x kernels too.
>
> Right. It's currently scheduled for:
>   812   C out 18 Greg Kroah-Hart (1,7K) [PATCH 4.14 26/39] sctp:
> account stream padding length for re
>   813   C out 18 Greg Kroah-Hart (1,7K) [PATCH 4.19 33/50] sctp:
> account stream padding length for re
>   814   C out 18 Greg Kroah-Hart (1,7K) [PATCH 5.4 45/69] sctp: account
> stream padding length for rec
>   815   C out 18 Greg Kroah-Hart (1,7K) [PATCH 5.10 068/103] sctp:
> account stream padding length for
>   817   C out 18 Greg Kroah-Hart (1,7K) [PATCH 5.14 098/151] sctp:
> account stream padding length for
>
> > There is suppose to be a format to cc the syz-kaller bot to mark
> > 317ef02b0d5cbd19d445294fed91453c7f970fc3 fixed with commit
> > a2d859e3fc97e79d907761550dbc03ff1b36479c.
> >
> > Perhaps mentioning it here will be enough ;-) .
>
> Almost :-)
>
> The report I previously had for this issue didn't come from syzkaller.
> I'm not sure if 317ef02 above refers to the Google's instance of what.
> Anyway, would mind marking it as fixed then?
>
> Thanks!
> Marcelo

Hi Marcelo,

I posted this fix to syzkaller  google group list :

https://groups.google.com/g/syzkaller-bugs/c/8fwxxnZxy4s

Since you fixing it in so many LTS threads I suspect it is covered  for 
the most part.

Thank you && all the best !

JD

...