From 8466db95431f39fd8eec0ce057eab5e4711307de Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 11 Oct 2019 16:34:19 +0300 Subject: RDMA/uverbs: Prevent potential underflow [ Upstream commit a9018adfde809d44e71189b984fa61cc89682b5e ] The issue is in drivers/infiniband/core/uverbs_std_types_cq.c in the UVERBS_HANDLER(UVERBS_METHOD_CQ_CREATE) function. We check that: if (attr.comp_vector >= attrs->ufile->device->num_comp_vectors) { But we don't check if "attr.comp_vector" is negative. It could potentially lead to an array underflow. My concern would be where cq->vector is used in the create_cq() function from the cxgb4 driver. And really "attr.comp_vector" is appears as a u32 to user space so that's the right type to use. Fixes: 9ee79fce3642 ("IB/core: Add completion queue (cq) object actions") Link: https://lore.kernel.org/r/20191011133419.GA22905@mwanda Signed-off-by: Dan Carpenter Reviewed-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/core/uverbs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/infiniband') diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h index 37c8903e7fd0..8d79a48ccd38 100644 --- a/drivers/infiniband/core/uverbs.h +++ b/drivers/infiniband/core/uverbs.h @@ -87,7 +87,7 @@ struct ib_uverbs_device { atomic_t refcount; - int num_comp_vectors; + u32 num_comp_vectors; struct completion comp; struct device *dev; struct ib_device __rcu *ib_dev; -- cgit v1.2.3