[PATCH 5.11 419/601] IB/isert: Fix a use after free in isert_connect_request

Greg Kroah-Hartman
2021-05-12T17:41:51Z

From: Lv Yunlong <lyl2019@mail.ustc.edu.cn>

[ Upstream commit adb76a520d068a54ee5ca82e756cf8e5a47363a4 ]

The device is got by isert_device_get() with refcount is 1, and is
assigned to isert_conn by
isert_conn->device = device.

When isert_create_qp() failed, device will be freed with
isert_device_put().

Later, the device is used in isert_free_login_buf(isert_conn) by the
isert_conn->device->ib_device statement.

Free the device in the correct order.

Fixes: ae9ea9ed38c9 ("iser-target: Split some logic in isert_connect_request to routines")
Link: https://lore.kernel.org/r/20210322161325.7491-1-lyl2019@mail.ustc.edu.cn
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/ulp/isert/ib_isert.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 2ba27221ea85..11339cc72214 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -438,23 +438,23 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
isert_init_conn(isert_conn);
isert_conn->cm_id = cma_id;

- ret = isert_alloc_login_buf(isert_conn, cma_id->device);
- if (ret)
- goto out;
-
device = isert_device_get(cma_id);
if (IS_ERR(device)) {
ret = PTR_ERR(device);
- goto out_rsp_dma_map;
+ goto out;
}
isert_conn->device = device;

+ ret = isert_alloc_login_buf(isert_conn, cma_id->device);
+ if (ret)
+ goto out_conn_dev;
+
isert_set_nego_params(isert_conn, &event->param.conn);

isert_conn->qp = isert_create_qp(isert_conn, cma_id);
if (IS_ERR(isert_conn->qp)) {
ret = PTR_ERR(isert_conn->qp);
- goto out_conn_dev;
+ goto out_rsp_dma_map;
}

ret = isert_login_post_recv(isert_conn);
@@ -473,10 +473,10 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)

out_destroy_qp:
isert_destroy_qp(isert_conn);
-out_conn_dev:
- isert_device_put(device);
out_rsp_dma_map:
isert_free_login_buf(isert_conn);
+out_conn_dev:
+ isert_device_put(device);
out:
kfree(isert_conn);
rdma_reject(cma_id, NULL, 0, IB_CM_REJ_CONSUMER_DEFINED);
--
2.30.2