4.9-stable review patch. If anyone has any objections, please let me know.
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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 @@ -706,8 +706,10 @@ 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 @@ -448,8 +448,10 @@ 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);