In ath12k_dp_tx(), if we reach fail_dma_unmap due to some errors, current code does DMA unmap unconditionally on skb_cb->paddr_ext_desc. However, skb_cb->paddr_ext_desc may be NULL and thus we get below warning: kernel: [ 8887.076212] WARNING: CPU: 3 PID: 0 at drivers/iommu/dma-iommu.c:1077 iommu_dma_unmap_page+0x79/0x90 Fix it by checking skb_cb->paddr_ext_desc before unmap it. Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4 Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices") Signed-off-by: Baochen Qiang <quic_bqiang@xxxxxxxxxxx> --- drivers/net/wireless/ath/ath12k/dp_tx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/ath12k/dp_tx.c b/drivers/net/wireless/ath/ath12k/dp_tx.c index 8874c815d7fa..c0ae2fd443cc 100644 --- a/drivers/net/wireless/ath/ath12k/dp_tx.c +++ b/drivers/net/wireless/ath/ath12k/dp_tx.c @@ -330,8 +330,10 @@ int ath12k_dp_tx(struct ath12k *ar, struct ath12k_vif *arvif, fail_unmap_dma: dma_unmap_single(ab->dev, ti.paddr, ti.data_len, DMA_TO_DEVICE); - dma_unmap_single(ab->dev, skb_cb->paddr_ext_desc, - sizeof(struct hal_tx_msdu_ext_desc), DMA_TO_DEVICE); + if (skb_cb->paddr_ext_desc) + dma_unmap_single(ab->dev, skb_cb->paddr_ext_desc, + sizeof(struct hal_tx_msdu_ext_desc), + DMA_TO_DEVICE); fail_remove_tx_buf: ath12k_dp_tx_release_txbuf(dp, tx_desc, pool_id); base-commit: a62b0aeb556839fb6abb9835874443b08fe95598 -- 2.25.1