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

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@quicinc.com>
Acked-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
Acked-by: Kalle Valo <kvalo@kernel.org>
Link: https://patch.msgid.link/20241210-read_after_free-v1-1-969f69c7d66c@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index c4eab4c1c10e0a05248fb58858dac9a00ef2e799..47a80d28d1d7f83ae7f61ecb89c6cd7d1d779494 100644 (file)
--- 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);