[PATCH] wifi: ath12k: fix read pointer after free in ath12k_mac_assign_vif_to_vdev()

[Aditya Kumar Singh]

In ath12k_mac_assign_vif_to_vdev(), if arvif is created on a different
radio, it gets deleted from that radio through a call to
ath12k_mac_unassign_link_vif(). This action frees the arvif pointer.
Subsequently, there is a check involving arvif, which will result in a
read-after-free scenario.

Fix this by moving this check after arvif is again assigned via call to
ath12k_mac_assign_link_vif().

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1

Closes: https://scan5.scan.coverity.com/#/project-view/63541/10063?selectedIssue=1636423
Fixes: b5068bc9180d ("wifi: ath12k: Cache vdev configs before vdev create")
Signed-off-by: Aditya Kumar Singh <quic_adisi@xxxxxxxxxxx>
---
 drivers/net/wireless/ath/ath12k/mac.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index c4eab4c1c10e0a05248fb58858dac9a00ef2e799..47a80d28d1d7f83ae7f61ecb89c6cd7d1d779494 100644
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -8064,9 +8064,6 @@ static struct ath12k *ath12k_mac_assign_vif_to_vdev(struct ieee80211_hw *hw,
 
 	ab = ar->ab;
 
-	if (arvif->is_created)
-		goto flush;
-
 	/* Assign arvif again here since previous radio switch block
 	 * would've unassigned and cleared it.
 	 */
@@ -8077,6 +8074,9 @@ static struct ath12k *ath12k_mac_assign_vif_to_vdev(struct ieee80211_hw *hw,
 		goto unlock;
 	}
 
+	if (arvif->is_created)
+		goto flush;
+
 	if (ar->num_created_vdevs > (TARGET_NUM_VDEVS - 1)) {
 		ath12k_warn(ab, "failed to create vdev, reached max vdev limit %d\n",
 			    TARGET_NUM_VDEVS);

---
base-commit: 27909c77d085d32db141cbb32b2cc9fbef874197
change-id: 20241210-read_after_free-4e22cbdc1ed8