From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leon Romanovsky Subject: [PATCH rdma-next 06/12] RDMA/uverbs: Don't overwrite NULL pointer with ZERO_SIZE_PTR Date: Sun, 24 Jun 2018 11:23:47 +0300 Message-ID: <20180624082353.16138-7-leon@kernel.org> References: <20180624082353.16138-1-leon@kernel.org> Cc: Leon Romanovsky , RDMA mailing list , Hadar Hen Zion , Matan Barak , Michael J Ruhl , Noa Osherovich , Raed Salem , Yishai Hadas , Saeed Mahameed , linux-netdev To: Doug Ledford , Jason Gunthorpe Return-path: Received: from mail.kernel.org ([198.145.29.99]:52816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751823AbeFXIYR (ORCPT ); Sun, 24 Jun 2018 04:24:17 -0400 In-Reply-To: <20180624082353.16138-1-leon@kernel.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Leon Romanovsky Number of specs is provided by user and in valid case can be equal to zero. Such argument causes to call to kcalloc() with zero-length request and in return the ZERO_SIZE_PTR is assigned. This pointer is different from NULL and makes various if (..) checks to success. Fixes: b6ba4a9aa59f ("IB/uverbs: Add support for flow counters") Signed-off-by: Leon Romanovsky --- drivers/infiniband/core/uverbs_cmd.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c index 3aba63aa1779..8ed4b674416f 100644 --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -2768,6 +2768,9 @@ static struct ib_uflow_resources *flow_resources_alloc(size_t num_specs) if (!resources) return NULL; + if (!num_specs) + goto out; + resources->counters = kcalloc(num_specs, sizeof(*resources->counters), GFP_KERNEL); resources->collection = @@ -2776,8 +2779,8 @@ static struct ib_uflow_resources *flow_resources_alloc(size_t num_specs) if (!resources->counters || !resources->collection) goto err; +out: resources->max = num_specs; - return resources; err: -- 2.14.4