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Re: [PATCH 2/3] zram: do not use copy_page with non-page alinged address

From Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Newsgroups linux.kernel
Subject Re: [PATCH 2/3] zram: do not use copy_page with non-page alinged address
Date 2017-04-14 07:50 +0200
Message-ID <tw2hj-5Fi-1@gated-at.bofh.it> (permalink)
References <tvAEp-3qZ-3@gated-at.bofh.it> <tvAEq-3qZ-17@gated-at.bofh.it>
Organization linux.* mail to news gateway

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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

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Thread

[PATCH 1/3] zram: fix operator precedence to get offset Minchan Kim <minchan@kernel.org> - 2017-04-13 02:20 +0200
  [PATCH 3/3] zsmalloc: expand class bit Minchan Kim <minchan@kernel.org> - 2017-04-13 02:20 +0200
  [PATCH 2/3] zram: do not use copy_page with non-page alinged address Minchan Kim <minchan@kernel.org> - 2017-04-13 02:20 +0200
    Re: [PATCH 2/3] zram: do not use copy_page with non-page alinged  address Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-14 07:50 +0200
      Re: [PATCH 2/3] zram: do not use copy_page with non-page alinged  address Minchan Kim <minchan@kernel.org> - 2017-04-14 17:50 +0200
    Re: [PATCH 2/3] zram: do not use copy_page with non-page alinged  address Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-17 03:50 +0200
  Re: [PATCH 1/3] zram: fix operator precedence to get offset Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-14 07:10 +0200
    Re: [PATCH 1/3] zram: fix operator precedence to get offset Minchan Kim <minchan@kernel.org> - 2017-04-14 17:40 +0200
      Re: [PATCH 1/3] zram: fix operator precedence to get offset Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-17 03:30 +0200
        Re: [PATCH 1/3] zram: fix operator precedence to get offset Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-17 04:00 +0200
          Re: [PATCH 1/3] zram: fix operator precedence to get offset Minchan Kim <minchan@kernel.org> - 2017-04-17 04:20 +0200
            Re: [PATCH 1/3] zram: fix operator precedence to get offset Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-17 13:00 +0200
              Re: [PATCH 1/3] zram: fix operator precedence to get offset Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-17 13:00 +0200
              Re: [PATCH 1/3] zram: fix operator precedence to get offset Minchan Kim <minchan@kernel.org> - 2017-04-18 02:00 +0200
                Re: [PATCH 1/3] zram: fix operator precedence to get offset Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-18 04:00 +0200
                Re: [PATCH 1/3] zram: fix operator precedence to get offset Minchan Kim <minchan@kernel.org> - 2017-04-18 04:50 +0200
  Re: [PATCH 1/3] zram: fix operator precedence to get offset Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-04-17 03:30 +0200

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