From: Mel Gorman <mgorman@techsingularity.net>
To: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] mm/page_alloc: avoid potential NULL pointer dereference
Date: Tue, 23 Apr 2019 15:35:40 +0100 [thread overview]
Message-ID: <20190423143540.GQ18914@techsingularity.net> (raw)
In-Reply-To: <20190423120806.3503-1-aryabinin@virtuozzo.com>
On Tue, Apr 23, 2019 at 03:08:05PM +0300, Andrey Ryabinin wrote:
> ac.preferred_zoneref->zone passed to alloc_flags_nofragment() can be NULL.
> 'zone' pointer unconditionally derefernced in alloc_flags_nofragment().
> Bail out on NULL zone to avoid potential crash.
> Currently we don't see any crashes only because alloc_flags_nofragment()
> has another bug which allows compiler to optimize away all accesses to
> 'zone'.
>
> Fixes: 6bb154504f8b ("mm, page_alloc: spread allocations across zones before introducing fragmentation")
> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
--
Mel Gorman
SUSE Labs
prev parent reply other threads:[~2019-04-23 14:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-23 12:08 [PATCH 1/2] mm/page_alloc: avoid potential NULL pointer dereference Andrey Ryabinin
2019-04-23 12:08 ` [PATCH 2/2] mm/page_alloc: fix never set ALLOC_NOFRAGMENT flag Andrey Ryabinin
2019-04-23 14:35 ` Mel Gorman
2019-04-23 19:01 ` Andrew Morton
2019-04-24 9:04 ` Mel Gorman
2019-04-24 22:46 ` Andrew Morton
2019-04-24 23:40 ` Mel Gorman
2019-04-25 21:09 ` Andrew Morton
2019-04-23 14:35 ` Mel Gorman [this message]
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