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From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Minchan Kim <minchan@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	kernel-team@lge.com, stable@vger.kernel.org
Subject: Re: [PATCH 2/3] zram: do not use copy_page with non-page alinged address
Date: Fri, 14 Apr 2017 14:41:05 +0900	[thread overview]
Message-ID: <20170414054105.GC462@jagdpanzerIV.localdomain> (raw)
In-Reply-To: <1492042622-12074-2-git-send-email-minchan@kernel.org>

Hello,

On (04/13/17 09:17), Minchan Kim wrote:
> The copy_page is optimized memcpy for page-alinged address.
> If it is used with non-page aligned address, it can corrupt memory which
> means system corruption. With zram, it can happen with
> 
> 1. 64K architecture
> 2. partial IO
> 3. slub debug
> 
> Partial IO need to allocate a page and zram allocates it via kmalloc.
> With slub debug, kmalloc(PAGE_SIZE) doesn't return page-size aligned
> address. And finally, copy_page(mem, cmem) corrupts memory.

which would be the case for many other copy_page() calls in the kernel.
right? if so - should the fix be in copy_page() then?

	-ss

  reply	other threads:[~2017-04-14  5:41 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-13  0:17 [PATCH 1/3] zram: fix operator precedence to get offset Minchan Kim
2017-04-13  0:17 ` [PATCH 2/3] zram: do not use copy_page with non-page alinged address Minchan Kim
2017-04-14  5:41   ` Sergey Senozhatsky [this message]
2017-04-14 15:40     ` Minchan Kim
2017-04-17  1:48   ` Sergey Senozhatsky
2017-04-13  0:17 ` [PATCH 3/3] zsmalloc: expand class bit Minchan Kim
2017-04-14  5:07 ` [PATCH 1/3] zram: fix operator precedence to get offset Sergey Senozhatsky
2017-04-14 15:33   ` Minchan Kim
2017-04-17  1:21     ` Sergey Senozhatsky
2017-04-17  1:54       ` Sergey Senozhatsky
2017-04-17  2:14         ` Minchan Kim
2017-04-17 10:50           ` Sergey Senozhatsky
2017-04-17 10:53             ` Sergey Senozhatsky
2017-04-17 23:53             ` Minchan Kim
2017-04-18  1:53               ` Sergey Senozhatsky
2017-04-18  2:47                 ` Minchan Kim
2017-04-17  1:21 ` Sergey Senozhatsky

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