Re: KASAN: use-after-free Read in rxe_query_port

From: Jason Gunthorpe
Date: Tue Mar 10 2020 - 10:52:30 EST


On Tue, Mar 10, 2020 at 09:39:36AM +0200, Leon Romanovsky wrote:
> On Mon, Mar 09, 2020 at 02:34:51PM -0300, Jason Gunthorpe wrote:
> > On Sun, Mar 01, 2020 at 03:20:12AM -0800, syzbot wrote:
> > > Hello,
> > >
> > > syzbot found the following crash on:
> > >
> > > HEAD commit: f8788d86 Linux 5.6-rc3
> > > git tree: upstream
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=132d3645e00000
> > > kernel config: https://syzkaller.appspot.com/x/.config?x=9833e26bab355358
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=e11efb687f5ab7f01f3d
> > > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> > >
> > > Unfortunately, I don't have any reproducer for this crash yet.
> > >
> > > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > > Reported-by: syzbot+e11efb687f5ab7f01f3d@xxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > Yanjun, do you have some idea what this could be?
>
> See this fix in the net mailing list.
> https://lore.kernel.org/netdev/20200306134518.84416-1-kgraul@xxxxxxxxxxxxx

Yes, seems right to me, that work is calling ib_query_port().

#syz dup: WARNING: ODEBUG bug in smc_ib_remove_dev

Jason