[Devel] [PATCH RHEL7 COMMIT] ms/crypto: scatterwalk - Fix test in scatterwalk_done

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-327.36.1.vz7.19.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-327.36.1.vz7.19.3
------>
commit ed0a88a97ef0a6400759a47a32fb61597de28433
Author: Herbert Xu <herbert at gondor.apana.org.au>
Date:   Mon Oct 24 16:34:09 2016 +0400

    ms/crypto: scatterwalk - Fix test in scatterwalk_done
    
    When there is more data to be processed, the current test in
    scatterwalk_done may prevent us from calling pagedone even when
    we should.
    
    In particular, if we're on an SG entry spanning multiple pages
    where the last page is not a full page, we will incorrectly skip
    calling pagedone on the second last page.
    
    This patch fixes this by adding a separate test for whether we've
    reached the end of a page.
    
    Cc: stable at vger.kernel.org
    Signed-off-by: Herbert Xu <herbert at gondor.apana.org.au>
    (cherry picked from commit 5f070e81bee35f1b7bd1477bb223a873ff657803)
    Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
 crypto/scatterwalk.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
index 7281b8a..79cbbbf 100644
--- a/crypto/scatterwalk.c
+++ b/crypto/scatterwalk.c
@@ -68,7 +68,8 @@ static void scatterwalk_pagedone(struct scatter_walk *walk, int out,
 
 void scatterwalk_done(struct scatter_walk *walk, int out, int more)
 {
-	if (!(scatterwalk_pagelen(walk) & (PAGE_SIZE - 1)) || !more)
+	if (!more || walk->offset >= walk->sg->offset + walk->sg->length ||
+	    !(walk->offset & (PAGE_SIZE - 1)))
 		scatterwalk_pagedone(walk, out, more);
 }
 EXPORT_SYMBOL_GPL(scatterwalk_done);