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: v4.19-rc1~106^2~235 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=a5cc9831af05e658543593abaee45a29d061bac4;p=linux.git RDMA/uverbs: Don't overwrite NULL pointer with ZERO_SIZE_PTR 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 --- diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c index 74c5bc934822..7d70d17a853a 100644 --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -2763,6 +2763,9 @@ 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 = @@ -2771,8 +2774,8 @@ 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: