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

From: Christian Marangi
Date: Thu Feb 09 2023 - 17:27:11 EST


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.

Fixes: d673cb6fe6c0 ("wifi: ath11k: fix peer addition/deletion error on sta band migration")
Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Signed-off-by: Christian Marangi <ansuelsmth@xxxxxxxxx>
---
drivers/net/wireless/ath/ath11k/peer.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/peer.c b/drivers/net/wireless/ath/ath11k/peer.c
index 1ae7af02c364..1380811827a8 100644
--- 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) {
--
2.38.1