Re: general protection fault in put_pid

[Manfred Spraul]

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Hello Dmitry,

On 12/12/18 11:55 AM, Dmitry Vyukov wrote:
> On Tue, Dec 11, 2018 at 9:23 PM syzbot
> <syzbot+1145ec2e23165570c3ac@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit:    f5d582777bcb Merge branch 'for-linus' of git://git.kernel...
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=135bc547400000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23
> > dashboard link: https://syzkaller.appspot.com/bug?extid=1145ec2e23165570c3ac
> > compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16803afb400000
> +Manfred, this looks similar to the other few crashes related to
> semget$private(0x0, 0x4000, 0x3f) that you looked at.

I found one unexpected (incorrect?) locking, see the attached patch.

But I doubt that this is the root cause of the crashes.

Any remarks on the patch?

I would continue to search, and then send a series with all findings.

--

ÂÂÂ Manfred