[PATCH] Endian swap ->count before handing over to the nx-842 compressor

[PATCH] Endian swap ->count before handing over to the nx-842 compressor

[Ram Pai]

The nx-842 compressor overshoots the output buffer corrupting memory. Verified
that the following patch the issue on a LE system.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
 drivers/crypto/nx/nx-842-powernv.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c
index 3750e13..3b80ea7 100644
--- a/drivers/crypto/nx/nx-842-powernv.c
+++ b/drivers/crypto/nx/nx-842-powernv.c
@@ -66,7 +66,7 @@ static void setup_indirect_dde(struct data_descriptor_entry *dde,
 			       unsigned int dde_count, unsigned int byte_count)
 {
 	dde->flags = 0;
-	dde->count = dde_count;
+	dde->count = cpu_to_be32(dde_count);
 	dde->index = 0;
 	dde->length = cpu_to_be32(byte_count);
 	dde->address = cpu_to_be64(nx842_get_pa(ddl));
-- 
1.7.1

Re: [PATCH] Endian swap ->count before handing over to the nx-842 compressor

[Michael Ellerman]

On Fri, 2015-10-30 at 15:13 -0700, Ram Pai wrote:

> The nx-842 compressor overshoots the output buffer corrupting memory. Verified
> that the following patch the issue on a LE system.

This seems like a bug fix, so it should go to stable shouldn't it? If so which
version(s) should it apply to?

And which commit introduced the breakage? Or has it always been broken?

cheers

Re: [PATCH] Endian swap ->count before handing over to the nx-842 compressor

[Ram Pai]

On Mon, Nov 02, 2015 at 12:24:36PM +1100, Michael Ellerman wrote:
> On Fri, 2015-10-30 at 15:13 -0700, Ram Pai wrote:
> 
> > The nx-842 compressor overshoots the output buffer corrupting memory. Verified
> > that the following patch the issue on a LE system.
> 
> This seems like a bug fix, so it should go to stable shouldn't it? If so which
> version(s) should it apply to?
> 
> And which commit introduced the breakage? Or has it always been broken?

Mike,

	Please ignore this patch. I still run into corruption even after
	this patch.  I am looking into the issue. Will have a more
	comprehensive fix.

	BTW: it has always been broken AFAICT. I find the issue even
	with lzo software compression. So may be I am doing something
	wrong in my driver, or there is more fundamental issue. Will dig
	this further.

RP

> 
> cheers

-- 
Ram Pai