[PATCH] i40iw: Add a value assignment to avoid sleep-in-atomic bug caused by uninitialized value

From: Jia-Ju Bai
Date: Wed May 31 2017 - 22:10:01 EST


The value "cqp_request->waiting" indicates whether the sleeping operation
should be performed, and it is not assigned in i40iw_get_cqp_request, so
the driver may sleep in interrupt handling. The function call path is:

i40iw_dpc (tasklet_init indicates it handles interrupt)
i40iw_process_aeq
i40iw_next_iw_state
i40iw_hw_modify_qp (call i40iw_get_cqp_request)
i40iw_handle_cqp_op
i40iw_wait_event --> may sleep

To fix it, "cqp_request->waiting" is assigned in "else" branch in
i40iw_get_cqp_request.

Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxx>
---
drivers/infiniband/hw/i40iw/i40iw_utils.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/infiniband/hw/i40iw/i40iw_utils.c b/drivers/infiniband/hw/i40iw/i40iw_utils.c
index 409a378..0f4e633 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_utils.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_utils.c
@@ -326,6 +326,7 @@ struct i40iw_cqp_request *i40iw_get_cqp_request(struct i40iw_cqp *cqp, bool wait
cqp_request->waiting = true;
} else {
atomic_set(&cqp_request->refcount, 1);
+ cqp_request->waiting = false;
}
return cqp_request;
}
--
1.7.9.5