Patch "rhashtable: Fix rhlist duplicates insertion" has been added to the 4.15-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    rhashtable: Fix rhlist duplicates insertion

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     rhashtable-fix-rhlist-duplicates-insertion.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Wed Mar 28 18:37:51 CEST 2018
From: Paul Blakey <paulb@mellanox.com>
Date: Sun, 4 Mar 2018 17:29:48 +0200
Subject: rhashtable: Fix rhlist duplicates insertion

From: Paul Blakey <paulb@mellanox.com>


[ Upstream commit d3dcf8eb615537526bd42ff27a081d46d337816e ]

When inserting duplicate objects (those with the same key),
current rhlist implementation messes up the chain pointers by
updating the bucket pointer instead of prev next pointer to the
newly inserted node. This causes missing elements on removal and
travesal.

Fix that by properly updating pprev pointer to point to
the correct rhash_head next pointer.

Issue: 1241076
Change-Id: I86b2c140bcb4aeb10b70a72a267ff590bb2b17e7
Fixes: ca26893f05e8 ('rhashtable: Add rhlist interface')
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/linux/rhashtable.h |    4 +++-
 lib/rhashtable.c           |    4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -750,8 +750,10 @@ slow_path:
 		if (!key ||
 		    (params.obj_cmpfn ?
 		     params.obj_cmpfn(&arg, rht_obj(ht, head)) :
-		     rhashtable_compare(&arg, rht_obj(ht, head))))
+		     rhashtable_compare(&arg, rht_obj(ht, head)))) {
+			pprev = &head->next;
 			continue;
+		}
 
 		data = rht_obj(ht, head);
 
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -537,8 +537,10 @@ static void *rhashtable_lookup_one(struc
 		if (!key ||
 		    (ht->p.obj_cmpfn ?
 		     ht->p.obj_cmpfn(&arg, rht_obj(ht, head)) :
-		     rhashtable_compare(&arg, rht_obj(ht, head))))
+		     rhashtable_compare(&arg, rht_obj(ht, head)))) {
+			pprev = &head->next;
 			continue;
+		}
 
 		if (!ht->rhlist)
 			return rht_obj(ht, head);


Patches currently in stable-queue which might be from paulb@mellanox.com are

queue-4.15/rhashtable-fix-rhlist-duplicates-insertion.patch
queue-4.15/test_rhashtable-add-test-case-for-rhltable-with-duplicate-objects.patch