Re: zram: fix invalid memory references during disk write

From: Greg KH
Date: Tue Dec 11 2012 - 13:27:12 EST


On Thu, Nov 29, 2012 at 10:45:09PM -0800, Nitin Gupta wrote:
> Fixes a bug introduced by commit c8f2f0db1 ("zram: Fix handling
> of incompressible pages") which caused invalid memory references
> during disk write. Invalid references could occur in two cases:
> - Incoming data expands on compression: In this case, reference was
> made to kunmap()'ed bio page.
> - Partial (non PAGE_SIZE) write with incompressible data: In this
> case, reference was made to a kfree()'ed buffer.
>
> Fixes bug 50081:
> https://bugzilla.kernel.org/show_bug.cgi?id=50081
>
> Upstream commit ID: c8f2f0d: zram: Fix handling of incompressible pages
> Apply to versions: 3.6.5, 3.6.6, 3.6.7, 3.6.8
>
> Cc: <stable@xxxxxxxxxxxxxxx> # staging-next: 37b51fd: zram: factor-out
> # zram_decompress_page() function
> Signed-off-by: Nitin Gupta <ngupta@xxxxxxxxxx>
> Reported-by: Mihail Kasadjikov <hamer.mk@xxxxxxxxx>
> Reported-by: Tomas M <tomas@xxxxxxxx>
> Reviewed-by: Minchan Kim <minchan@xxxxxxxxxx>
> ---
> drivers/staging/zram/zram_drv.c | 39 ++++++++++++++++++++++++---------------
> 1 file changed, 24 insertions(+), 15 deletions(-)

This patch fails to apply to 3.6.10:

patching file drivers/staging/zram/zram_drv.c
Hunk #1 succeeded at 282 (offset 17 lines).
Hunk #2 FAILED at 286.
Hunk #3 succeeded at 319 (offset 17 lines).
Hunk #4 succeeded at 340 (offset 17 lines).
Hunk #5 succeeded at 353 (offset 17 lines).
Hunk #6 succeeded at 368 (offset 17 lines).
Hunk #7 succeeded at 385 (offset 17 lines).
1 out of 7 hunks FAILED -- saving rejects to file drivers/staging/zram/zram_drv.c.rej

Please redo this patch and resend it if you wish for it to be applied to
the 3.6-stable tree.

thanks,

greg k-h
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