Re: WARNING in cma_exit_net

[Leon Romanovsky <leon@kernel.org>]

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On Tue, Apr 02, 2019 at 04:39:12PM -0700, Bart Van Assche wrote:
> On Mon, 2019-04-01 at 21:29 +0300, Leon Romanovsky wrote:
> > On Mon, Apr 01, 2019 at 02:45:54PM -0300, Jason Gunthorpe wrote:
> > > On Mon, Apr 01, 2019 at 10:36:05AM -0700, syzbot wrote:
> > > > Hello,
> > > >
> > > > syzbot found the following crash on:
> > > >
> > > > HEAD commit:    e3ecb83e Add linux-next specific files for 20190401
> > > > git tree:       linux-next
> > > > console output: https://syzkaller.appspot.com/x/log.txt?x=13bc36cd200000
> > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=db6c9f2bfeb91a99
> > > > dashboard link: https://syzkaller.appspot.com/bug?extid=2e3e485d5697ea610460
> > > > 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+2e3e485d5697ea610460@syzkaller.appspotmail.com
> > > >
> > > > WARNING: CPU: 1 PID: 7 at drivers/infiniband/core/cma.c:4674
> > > > cma_exit_net+0x327/0x390 drivers/infiniband/core/cma.c:4674
> > > > Kernel panic - not syncing: panic_on_warn set ...
> > >
> > > Matt: This is why the WARN_ON(!xa_empty()) is so valuable. Magically
> > > syzkaller can find something in this code is buggy.
> > >
> > > Mellanox is also showing a different testing failure over the weekend
> > > (use after free or something) from your 'cma: Convert portspace IDRs
> > > to XArray'
> >
> > This is what I see in my environment.

Bart,

This patch [1] will fix it.

Thanks

[1] https://patchwork.kernel.org/patch/10881501/

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