[PATCH 4.14 20/23] RDMA/uverbs: Expand primary and alt AV port checks

Greg Kroah-Hartman
2018-08-04T09:04:25Z

From: Jack Morgenstein <jackm@dev.mellanox.co.il>

commit addb8a6559f0f8b5a37582b7ca698358445a55bf upstream.

The commit cited below checked that the port numbers provided in the
primary and alt AVs are legal.

That is sufficient to prevent a kernel panic. However, it is not
sufficient for correct operation.

In Linux, AVs (both primary and alt) must be completely self-described.
We do not accept an AV from userspace without an embedded port number.
(This has been the case since kernel 3.14 commit dbf727de7440
("IB/core: Use GID table in AH creation and dmac resolution")).

For the primary AV, this embedded port number must match the port number
specified with IB_QP_PORT.

We also expect the port number embedded in the alt AV to match the
alt_port_num value passed by the userspace driver in the modify_qp command
base structure.

Add these checks to modify_qp.

Cc: <stable@vger.kernel.org> # 4.16
Fixes: 5d4c05c3ee36 ("RDMA/uverbs: Sanitize user entered port numbers prior to access it")
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/infiniband/core/uverbs_cmd.c | 59 ++++++++++++++++++++++++++++++++---
1 file changed, 54 insertions(+), 5 deletions(-)

--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -1981,15 +1981,64 @@ static int modify_qp(struct ib_uverbs_fi
goto release_qp;
}

- if ((cmd->base.attr_mask & IB_QP_AV) &&
- !rdma_is_port_valid(qp->device, cmd->base.dest.port_num)) {
- ret = -EINVAL;
- goto release_qp;
+ if ((cmd->base.attr_mask & IB_QP_AV)) {
+ if (!rdma_is_port_valid(qp->device, cmd->base.dest.port_num)) {
+ ret = -EINVAL;
+ goto release_qp;
+ }
+
+ if (cmd->base.attr_mask & IB_QP_STATE &&
+ cmd->base.qp_state == IB_QPS_RTR) {
+ /* We are in INIT->RTR TRANSITION (if we are not,
+ * this transition will be rejected in subsequent checks).
+ * In the INIT->RTR transition, we cannot have IB_QP_PORT set,
+ * but the IB_QP_STATE flag is required.
+ *
+ * Since kernel 3.14 (commit dbf727de7440), the uverbs driver,
+ * when IB_QP_AV is set, has required inclusion of a valid
+ * port number in the primary AV. (AVs are created and handled
+ * differently for infiniband and ethernet (RoCE) ports).
+ *
+ * Check the port number included in the primary AV against
+ * the port number in the qp struct, which was set (and saved)
+ * in the RST->INIT transition.
+ */
+ if (cmd->base.dest.port_num != qp->real_qp->port) {
+ ret = -EINVAL;
+ goto release_qp;
+ }
+ } else {
+ /* We are in SQD->SQD. (If we are not, this transition will
+ * be rejected later in the verbs layer checks).
+ * Check for both IB_QP_PORT and IB_QP_AV, these can be set
+ * together in the SQD->SQD transition.
+ *
+ * If only IP_QP_AV was set, add in IB_QP_PORT as well (the
+ * verbs layer driver does not track primary port changes
+ * resulting from path migration. Thus, in SQD, if the primary
+ * AV is modified, the primary port should also be modified).
+ *
+ * Note that in this transition, the IB_QP_STATE flag
+ * is not allowed.
+ */
+ if (((cmd->base.attr_mask & (IB_QP_AV | IB_QP_PORT))
+ == (IB_QP_AV | IB_QP_PORT)) &&
+ cmd->base.port_num != cmd->base.dest.port_num) {
+ ret = -EINVAL;
+ goto release_qp;
+ }
+ if ((cmd->base.attr_mask & (IB_QP_AV | IB_QP_PORT))
+ == IB_QP_AV) {
+ cmd->base.attr_mask |= IB_QP_PORT;
+ cmd->base.port_num = cmd->base.dest.port_num;
+ }
+ }
}

if ((cmd->base.attr_mask & IB_QP_ALT_PATH) &&
(!rdma_is_port_valid(qp->device, cmd->base.alt_port_num) ||
- !rdma_is_port_valid(qp->device, cmd->base.alt_dest.port_num))) {
+ !rdma_is_port_valid(qp->device, cmd->base.alt_dest.port_num) ||
+ cmd->base.alt_port_num != cmd->base.alt_dest.port_num)) {
ret = -EINVAL;
goto release_qp;
}