2024-02-02 09:17:56

by William Kucharski

Subject: [PATCH v2 1/1] RDMA/srpt: Do not register event handler until srpt device is fully setup

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: dcc9881e6767 ("RDMA/(core, ulp): Convert register/unregister event handler to be void")
Signed-off-by: William Kucharski <[email protected]>
---
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 58f70cfec45a..d35f021f154b 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -3204,7 +3204,6 @@ 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];
@@ -3227,6 +3226,7 @@ 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);
@@ -3237,7 +3237,6 @@ 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);
--
2.39.3

2024-02-04 09:47:05

by Leon Romanovsky

Subject: Re: [PATCH v2 1/1] RDMA/srpt: Do not register event handler until srpt device is fully setup

On Fri, Feb 02, 2024 at 02:15:49AM -0700, William Kucharski wrote:
> 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: dcc9881e6767 ("RDMA/(core, ulp): Convert register/unregister event handler to be void")

This is wrong line, the issues is much older.
Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1")

> Signed-off-by: William Kucharski <[email protected]>

Please keep Reviewed-by tags provided by Bart.

Thanks