From: Leon Romanovsky Date: Sun, 24 Jun 2018 08:23:47 +0000 (+0300) Subject: RDMA/uverbs: Don't overwrite NULL pointer with ZERO_SIZE_PTR X-Git-Tag: v4.18.12~136 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=53b56e401d930d9d0ae148975c5c34f46df27b11;p=users%2Fdwmw2%2Flinux.git RDMA/uverbs: Don't overwrite NULL pointer with ZERO_SIZE_PTR [ Upstream commit a5cc9831af05e658543593abaee45a29d061bac4 ] 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 Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c index 583d3a10b9405..0e5eb0f547d39 100644 --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -2812,6 +2812,9 @@ static struct ib_uflow_resources *flow_resources_alloc(size_t num_specs) if (!resources) goto err_res; + if (!num_specs) + goto out; + resources->counters = kcalloc(num_specs, sizeof(*resources->counters), GFP_KERNEL); @@ -2824,8 +2827,8 @@ static struct ib_uflow_resources *flow_resources_alloc(size_t num_specs) if (!resources->collection) goto err_collection; +out: resources->max = num_specs; - return resources; err_collection: