[PATCH 6.7 566/713] RDMA/srpt: Do not register event handler until srpt device is fully setup

Sasha Levin
2024-03-24T22:56:43Z

From: William Kucharski <william.kucharski@oracle.com>

[ Upstream commit c21a8870c98611e8f892511825c9607f1e2cd456 ]

Upon rare occasions, KASAN reports a use-after-free Write
in srpt_refresh_port().

This seems to be because an event handler is registered before the
srpt device is fully setup and a race condition upon error may leave a
partially setup event handler in place.

Instead, only register the event handler after srpt device initialization
is complete.

Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1")
Signed-off-by: William Kucharski <william.kucharski@oracle.com>
Link: https://lore.kernel.org/r/20240202091549.991784-2-william.kucharski@oracle.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/ulp/srpt/ib_srpt.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 040234c01be4d..9632afbd727b6 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -3209,7 +3209,6 @@ static int srpt_add_one(struct ib_device *device)

INIT_IB_EVENT_HANDLER(&sdev->event_handler, sdev->device,
srpt_event_handler);
- ib_register_event_handler(&sdev->event_handler);

for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
sport = &sdev->port[i - 1];
@@ -3232,6 +3231,7 @@ static int srpt_add_one(struct ib_device *device)
}
}

+ ib_register_event_handler(&sdev->event_handler);
spin_lock(&srpt_dev_lock);
list_add_tail(&sdev->list, &srpt_dev_list);
spin_unlock(&srpt_dev_lock);
@@ -3242,7 +3242,6 @@ static int srpt_add_one(struct ib_device *device)

err_port:
srpt_unregister_mad_agent(sdev, i);
- ib_unregister_event_handler(&sdev->event_handler);
err_cm:
if (sdev->cm_id)
ib_destroy_cm_id(sdev->cm_id);
--
2.43.0