[PATCH 5.16 0596/1017] RDMA/irdma: Prevent some integer underflows

Greg Kroah-Hartman
2022-04-05T12:56:54Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 6f6dbb819dfc1a35bcb8b709b5c83a3ea8beff75 ]

My static checker complains that:

drivers/infiniband/hw/irdma/ctrl.c:3605 irdma_sc_ceq_init()
warn: can subtract underflow 'info->dev->hmc_fpm_misc.max_ceqs'?

It appears that "info->dev->hmc_fpm_misc.max_ceqs" comes from the firmware
in irdma_sc_parse_fpm_query_buf() so, yes, there is a chance that it could
be zero. Even if we trust the firmware, it's easy enough to change the
condition just as a hardenning measure.

Fixes: 3f49d6842569 ("RDMA/irdma: Implement HW Admin Queue OPs")
Link: https://lore.kernel.org/r/20220307125928.GE16710@kili
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/hw/irdma/ctrl.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/infiniband/hw/irdma/ctrl.c b/drivers/infiniband/hw/irdma/ctrl.c
index 7264f8c2f7d5..1d6b578dbd82 100644
--- a/drivers/infiniband/hw/irdma/ctrl.c
+++ b/drivers/infiniband/hw/irdma/ctrl.c
@@ -431,7 +431,7 @@ enum irdma_status_code irdma_sc_qp_create(struct irdma_sc_qp *qp, struct irdma_c

cqp = qp->dev->cqp;
if (qp->qp_uk.qp_id < cqp->dev->hw_attrs.min_hw_qp_id ||
- qp->qp_uk.qp_id > (cqp->dev->hmc_info->hmc_obj[IRDMA_HMC_IW_QP].max_cnt - 1))
+ qp->qp_uk.qp_id >= (cqp->dev->hmc_info->hmc_obj[IRDMA_HMC_IW_QP].max_cnt))
return IRDMA_ERR_INVALID_QP_ID;

wqe = irdma_sc_cqp_get_next_send_wqe(cqp, scratch);
@@ -2510,10 +2510,10 @@ static enum irdma_status_code irdma_sc_cq_create(struct irdma_sc_cq *cq,
enum irdma_status_code ret_code = 0;

cqp = cq->dev->cqp;
- if (cq->cq_uk.cq_id > (cqp->dev->hmc_info->hmc_obj[IRDMA_HMC_IW_CQ].max_cnt - 1))
+ if (cq->cq_uk.cq_id >= (cqp->dev->hmc_info->hmc_obj[IRDMA_HMC_IW_CQ].max_cnt))
return IRDMA_ERR_INVALID_CQ_ID;

- if (cq->ceq_id > (cq->dev->hmc_fpm_misc.max_ceqs - 1))
+ if (cq->ceq_id >= (cq->dev->hmc_fpm_misc.max_ceqs))
return IRDMA_ERR_INVALID_CEQ_ID;

ceq = cq->dev->ceq[cq->ceq_id];
@@ -3615,7 +3615,7 @@ enum irdma_status_code irdma_sc_ceq_init(struct irdma_sc_ceq *ceq,
info->elem_cnt > info->dev->hw_attrs.max_hw_ceq_size)
return IRDMA_ERR_INVALID_SIZE;

- if (info->ceq_id > (info->dev->hmc_fpm_misc.max_ceqs - 1))
+ if (info->ceq_id >= (info->dev->hmc_fpm_misc.max_ceqs))
return IRDMA_ERR_INVALID_CEQ_ID;
pble_obj_cnt = info->dev->hmc_info->hmc_obj[IRDMA_HMC_IW_PBLE].cnt;

@@ -4164,7 +4164,7 @@ enum irdma_status_code irdma_sc_ccq_init(struct irdma_sc_cq *cq,
info->num_elem > info->dev->hw_attrs.uk_attrs.max_hw_cq_size)
return IRDMA_ERR_INVALID_SIZE;

- if (info->ceq_id > (info->dev->hmc_fpm_misc.max_ceqs - 1))
+ if (info->ceq_id >= (info->dev->hmc_fpm_misc.max_ceqs ))
return IRDMA_ERR_INVALID_CEQ_ID;

pble_obj_cnt = info->dev->hmc_info->hmc_obj[IRDMA_HMC_IW_PBLE].cnt;
--
2.34.1