wifi: ath11k: fix SAC bug on peer addition with sta band migration

[ Upstream commit 60b7d62ba8cdbd073997bff0f1cdae8d844002c0 ]

Fix sleep in atomic context warning detected by Smatch static checker
analyzer.

Following the locking pattern for peer_rhash_add lock tbl_mtx_lock mutex
always even if sta is not transitioning to another band.
This is peer_add function and a more secure locking should not cause
performance regression.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.5.0.1-01208-QCAHKSWPL_SILICONZ-1

Fixes: d673cb6fe6c0 ("wifi: ath11k: fix peer addition/deletion error on sta band migration")
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230209222622.1751-1-ansuelsmth@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/wireless/ath/ath11k/peer.c b/drivers/net/wireless/ath/ath11k/peer.c
index 1ae7af0..1380811 100644 (file)
--- a/drivers/net/wireless/ath/ath11k/peer.c
+++ b/drivers/net/wireless/ath/ath11k/peer.c
@@ -382,22 +382,23 @@ int ath11k_peer_create(struct ath11k *ar, struct ath11k_vif *arvif,
                return -ENOBUFS;
        }
 
+       mutex_lock(&ar->ab->tbl_mtx_lock);
        spin_lock_bh(&ar->ab->base_lock);
        peer = ath11k_peer_find_by_addr(ar->ab, param->peer_addr);
        if (peer) {
                if (peer->vdev_id == param->vdev_id) {
                        spin_unlock_bh(&ar->ab->base_lock);
+                       mutex_unlock(&ar->ab->tbl_mtx_lock);
                        return -EINVAL;
                }
 
                /* Assume sta is transitioning to another band.
                 * Remove here the peer from rhash.
                 */
-               mutex_lock(&ar->ab->tbl_mtx_lock);
                ath11k_peer_rhash_delete(ar->ab, peer);
-               mutex_unlock(&ar->ab->tbl_mtx_lock);
        }
        spin_unlock_bh(&ar->ab->base_lock);
+       mutex_unlock(&ar->ab->tbl_mtx_lock);
 
        ret = ath11k_wmi_send_peer_create_cmd(ar, param);
        if (ret) {