[PATCH v2] ath11k: fix a locking bug in ath11k_mac_op_start()

Dan Carpenter
2021-02-02T11:31:38Z

This error path leads to a Smatch warning:

drivers/net/wireless/ath/ath11k/mac.c:4269 ath11k_mac_op_start()
error: double unlocked '&ar->conf_mutex' (orig line 4251)

We're not holding the lock when we do the "goto err;" so it leads to a
double unlock. The fix is to hold the lock for a little longer.

Fixes: c83c500b55b6 ("ath11k: enable idle power save mode")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: reviewers were concern that v1 was racy

drivers/net/wireless/ath/ath11k/mac.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index c1608f64ea95..464d3425488b 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -4248,8 +4248,6 @@ static int ath11k_mac_op_start(struct ieee80211_hw *hw)
/* Configure the hash seed for hash based reo dest ring selection */
ath11k_wmi_pdev_lro_cfg(ar, ar->pdev->pdev_id);

- mutex_unlock(&ar->conf_mutex);
-
rcu_assign_pointer(ab->pdevs_active[ar->pdev_idx],
&ab->pdevs[ar->pdev_idx]);

@@ -4262,6 +4260,9 @@ static int ath11k_mac_op_start(struct ieee80211_hw *hw)
goto err;
}
}
+
+ mutex_unlock(&ar->conf_mutex);
+
return 0;

err:
--
2.30.0