RDMA/uverbs: Prevent potential underflow

[ Upstream commit a9018adfde ]

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: 9ee79fce36 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Dan Carpenter 2019-10-11 16:34:19 +03:00 committed by Greg Kroah-Hartman
parent d582769add
commit 027253315d
2 changed files with 2 additions and 2 deletions

View file

@ -98,7 +98,7 @@ ib_uverbs_init_udata_buf_or_null(struct ib_udata *udata,
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;

View file

@ -310,7 +310,7 @@ struct ib_tm_caps {
struct ib_cq_init_attr {
unsigned int cqe;
int comp_vector;
u32 comp_vector;
u32 flags;
};