From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 11 Oct 2019 16:34:19 +0300
Subject: RDMA/uverbs: Prevent potential underflow
Patch-mainline: v5.4-rc6
Git-commit: a9018adfde809d44e71189b984fa61cc89682b5e
References: jsc#SLE-8449 bnc#1151927 5.3.11
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 <dan.carpenter@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/core/uverbs.h | 2 +-
include/rdma/ib_verbs.h | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/infiniband/core/uverbs.h
+++ b/drivers/infiniband/core/uverbs.h
@@ -98,7 +98,7 @@ ib_uverbs_init_udata_buf_or_null(struct
struct ib_uverbs_device {
atomic_t refcount;
- int num_comp_vectors;
+ u32 num_comp_vectors;
struct completion comp;
struct device dev;
/* First group for device attributes, NULL terminated array */
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -366,7 +366,7 @@ struct ib_tm_caps {
struct ib_cq_init_attr {
unsigned int cqe;
- int comp_vector;
+ u32 comp_vector;
u32 flags;
};