From 37a068fc9dc4feb8d76e8896bb33883d06c11a6b Mon Sep 17 00:00:00 2001 From: P Praneesh Date: Fri, 11 Apr 2025 11:31:51 +0530 Subject: [PATCH] wifi: ath12k: Handle error cases during extended skb allocation Currently, in the case of extended skb allocation, the buffer is freed before the DMA unmap operation. This premature deletion can result in skb->data corruption, as the memory region could be re-allocated for other purposes. Fix this issue by reordering the failure cases by calling dma_unmap_single() first, then followed by the corresponding kfree_skb(). This helps avoid data corruption in case of failures in dp_tx(). Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1 Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3 Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices") Signed-off-by: P Praneesh Reviewed-by: Vasanthakumar Thiagarajan Link: https://patch.msgid.link/20250411060154.1388159-2-praneesh.p@oss.qualcomm.com Signed-off-by: Jeff Johnson --- drivers/net/wireless/ath/ath12k/dp_tx.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/net/wireless/ath/ath12k/dp_tx.c b/drivers/net/wireless/ath/ath12k/dp_tx.c index 91da0805706f..9d58a9a9cbff 100644 --- a/drivers/net/wireless/ath/ath12k/dp_tx.c +++ b/drivers/net/wireless/ath/ath12k/dp_tx.c @@ -231,7 +231,7 @@ int ath12k_dp_tx(struct ath12k *ar, struct ath12k_link_vif *arvif, struct ath12k_skb_cb *skb_cb = ATH12K_SKB_CB(skb); struct hal_tcl_data_cmd *hal_tcl_desc; struct hal_tx_msdu_ext_desc *msg; - struct sk_buff *skb_ext_desc; + struct sk_buff *skb_ext_desc = NULL; struct hal_srng *tcl_ring; struct ieee80211_hdr *hdr = (void *)skb->data; struct ath12k_vif *ahvif = arvif->ahvif; @@ -417,18 +417,15 @@ map: if (ret < 0) { ath12k_dbg(ab, ATH12K_DBG_DP_TX, "Failed to add HTT meta data, dropping packet\n"); - kfree_skb(skb_ext_desc); - goto fail_unmap_dma; + goto fail_free_ext_skb; } } ti.paddr = dma_map_single(ab->dev, skb_ext_desc->data, skb_ext_desc->len, DMA_TO_DEVICE); ret = dma_mapping_error(ab->dev, ti.paddr); - if (ret) { - kfree_skb(skb_ext_desc); - goto fail_unmap_dma; - } + if (ret) + goto fail_free_ext_skb; ti.data_len = skb_ext_desc->len; ti.type = HAL_TCL_DESC_TYPE_EXT_DESC; @@ -464,7 +461,7 @@ map: ring_selector++; } - goto fail_unmap_dma; + goto fail_unmap_dma_ext; } spin_lock_bh(&arvif->link_stats_lock); @@ -491,13 +488,16 @@ map: return 0; -fail_unmap_dma: - dma_unmap_single(ab->dev, ti.paddr, ti.data_len, DMA_TO_DEVICE); - +fail_unmap_dma_ext: 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_free_ext_skb: + kfree_skb(skb_ext_desc); + +fail_unmap_dma: + dma_unmap_single(ab->dev, ti.paddr, ti.data_len, DMA_TO_DEVICE); fail_remove_tx_buf: ath12k_dp_tx_release_txbuf(dp, tx_desc, pool_id); -- 2.50.1