From: Luka Gejak Date: Mon, 18 May 2026 14:23:11 +0000 (+0200) Subject: wifi: rtw88: usb: fix memory leaks on USB write failures X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=6b964941bbfe6e0f18b1a5e008486dbb62df440a;p=thirdparty%2Fkernel%2Flinux.git wifi: rtw88: usb: fix memory leaks on USB write failures When rtw_usb_write_port() fails to submit a USB Request Block (URB) (e.g., due to device disconnect or ENOMEM), the completion callback is never executed. Currently, the driver ignores the return value of rtw_usb_write_port() in rtw_usb_write_data() and rtw_usb_tx_agg_skb(). Because these functions rely on the completion callback to free the socket buffers (skbs) and the transaction control block (txcb), a submission failure results in: 1. A memory leak of the allocated skb in rtw_usb_write_data(). 2. A memory leak of the txcb structure and all aggregated skbs in rtw_usb_tx_agg_skb(). Fix this by checking the return value of rtw_usb_write_port(). If it fails, explicitly free the skb in rtw_usb_write_data(), and properly purge the tx_ack_queue and free the txcb in rtw_usb_tx_agg_skb(). The issue was discovered in practice during device disconnect/reconnect scenarios and memory pressure conditions. Tested by verifying normal TX operation continues after the fix without regressions. Fixes: a82dfd33d123 ("wifi: rtw88: Add common USB chip support") Cc: stable@vger.kernel.org Acked-by: Ping-Ke Shih Tested-by: Luka Gejak Signed-off-by: Luka Gejak Signed-off-by: Ping-Ke Shih Link: https://patch.msgid.link/20260518142311.10328-2-luka.gejak@linux.dev --- diff --git a/drivers/net/wireless/realtek/rtw88/usb.c b/drivers/net/wireless/realtek/rtw88/usb.c index 718940ebba31..1a0bdbf52cb0 100644 --- a/drivers/net/wireless/realtek/rtw88/usb.c +++ b/drivers/net/wireless/realtek/rtw88/usb.c @@ -399,6 +399,7 @@ static bool rtw_usb_tx_agg_skb(struct rtw_usb *rtwusb, struct sk_buff_head *list int agg_num = 0; unsigned int align_next = 0; u8 qsel; + int ret; if (skb_queue_empty(list)) return false; @@ -456,7 +457,13 @@ queue: tx_desc = (struct rtw_tx_desc *)skb_head->data; qsel = le32_get_bits(tx_desc->w1, RTW_TX_DESC_W1_QSEL); - rtw_usb_write_port(rtwdev, qsel, skb_head, rtw_usb_write_port_tx_complete, txcb); + ret = rtw_usb_write_port(rtwdev, qsel, skb_head, + rtw_usb_write_port_tx_complete, txcb); + if (ret) { + ieee80211_purge_tx_queue(rtwdev->hw, &txcb->tx_ack_queue); + kfree(txcb); + return false; + } return true; } @@ -518,8 +525,10 @@ static int rtw_usb_write_data(struct rtw_dev *rtwdev, ret = rtw_usb_write_port(rtwdev, qsel, skb, rtw_usb_write_port_complete, skb); - if (unlikely(ret)) + if (unlikely(ret)) { rtw_err(rtwdev, "failed to do USB write, ret=%d\n", ret); + dev_kfree_skb_any(skb); + } return ret; }