From: Manfred Spraul <manfred@colorfullife.com>
To: Dmitry Vyukov <dvyukov@google.com>,
syzkaller <syzkaller@googlegroups.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Hugh Dickins <hughd@google.com>, Joe Perches <joe@perches.com>,
sds@tycho.nsa.gov, Oleg Nesterov <oleg@redhat.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Rik van Riel <riel@redhat.com>,
mhocko@suse.cz, gang.chen.5i5j@gmail.com,
Peter Feiner <pfeiner@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Kostya Serebryany <kcc@google.com>,
Alexander Potapenko <glider@google.com>,
Andrey Konovalov <andreyknvl@google.com>,
Sasha Levin <sasha.levin@oracle.com>
Subject: Re: GPF in shm_lock ipc
Date: Sat, 2 Jan 2016 12:33:10 +0100 [thread overview]
Message-ID: <5687B576.7020303@colorfullife.com> (raw)
In-Reply-To: <CACT4Y+bwixTW5YZjPsN7qgCbhR=HR=SMoZi9yHfBaFWdqDkoXQ@mail.gmail.com>
Hi Dmitry,
shm locking differs too much from msg/sem locking, I never looked at it
in depth, so I'm not able to perform a proper review.
Except for the obvious: Races that can be triggered from user space are
inacceptable.
Regardless if there is a BUG_ON, a WARN_ON or nothing at all.
On 12/21/2015 04:44 PM, Dmitry Vyukov wrote:
>> +
>> +/* This is called by fork, once for every shm attach. */
>> +static void shm_open(struct vm_area_struct *vma)
>> +{
>> + int err = __shm_open(vma);
>> + /*
>> + * We raced in the idr lookup or with shm_destroy().
>> + * Either way, the ID is busted.
>> + */
>> + WARN_ON_ONCE(err);
>> }
Is it possible to trigger this race? Parallel IPC_RMID & fork()?
--
Manfred
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next prev parent reply other threads:[~2016-01-02 11:33 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-12 9:55 Dmitry Vyukov
2015-10-12 11:41 ` Vlastimil Babka
2015-10-12 11:44 ` Dmitry Vyukov
2015-10-12 12:27 ` Kirill A. Shutemov
2015-10-12 17:49 ` Davidlohr Bueso
2015-10-12 18:10 ` Kirill A. Shutemov
2015-10-12 18:55 ` Davidlohr Bueso
2015-10-13 3:18 ` Davidlohr Bueso
2015-10-13 12:30 ` Kirill A. Shutemov
2015-10-29 15:33 ` Dmitry Vyukov
2015-11-05 14:23 ` Kirill A. Shutemov
2015-12-21 15:44 ` Dmitry Vyukov
2016-01-02 11:33 ` Manfred Spraul [this message]
2016-01-02 12:19 ` Dmitry Vyukov
2016-01-02 15:58 ` Manfred Spraul
2016-02-02 3:25 ` Andrew Morton
2016-02-02 21:32 ` Dmitry Vyukov
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