From: Dan Carpenter Date: Fri, 11 Oct 2019 13:34:19 +0000 (+0300) Subject: RDMA/uverbs: Prevent potential underflow X-Git-Tag: v5.4-rc6~20^2~5 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a9018adfde809d44e71189b984fa61cc89682b5e;p=platform%2Fkernel%2Flinux-rpi.git RDMA/uverbs: Prevent potential underflow 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 --- diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h index 1e5aeb3..63f7f7d 100644 --- a/drivers/infiniband/core/uverbs.h +++ b/drivers/infiniband/core/uverbs.h @@ -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; /* First group for device attributes, NULL terminated array */ diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index 6a47ba8..e7e733a 100644 --- 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; };