From: Tristan Madani Date: Tue, 21 Apr 2026 11:14:34 +0000 (+0000) Subject: wifi: rtw88: fix OOB read from firmware RX descriptor exceeding DMA buffer X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=6e76e9ed273dfb4b3333a5ebbb94958cc5752ab6;p=thirdparty%2Fkernel%2Flinux.git wifi: rtw88: fix OOB read from firmware RX descriptor exceeding DMA buffer In rtw_pci_rx_napi(), new_len is computed as the sum of pkt_len (14-bit descriptor field, max 16383) and pkt_offset (drv_info_sz + shift, both firmware-controlled). The result can exceed RTK_PCI_RX_BUF_SIZE (11478), causing an out-of-bounds read from the pre-allocated DMA buffer when skb_put_data copies new_len bytes. The USB transport already validates this (rtw_usb_rx_data_put checks against RTW_USB_MAX_RECVBUF_SZ); the PCIe path does not. Add a check that new_len does not exceed the DMA buffer size. Fixes: e3037485c68e ("rtw88: new Realtek 802.11ac driver") Signed-off-by: Tristan Madani Signed-off-by: Ping-Ke Shih Link: https://patch.msgid.link/20260421111434.3389674-1-tristmd@gmail.com --- diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c index c56beacbb1b0..c2bf44e880cf 100644 --- a/drivers/net/wireless/realtek/rtw88/pci.c +++ b/drivers/net/wireless/realtek/rtw88/pci.c @@ -1077,6 +1077,11 @@ static u32 rtw_pci_rx_napi(struct rtw_dev *rtwdev, struct rtw_pci *rtwpci, * discard the frame if none available */ new_len = pkt_stat.pkt_len + pkt_offset; + if (unlikely(new_len > RTK_PCI_RX_BUF_SIZE)) { + rtw_dbg(rtwdev, RTW_DBG_RX, + "oversized RX packet: %u\n", new_len); + goto next_rp; + } new = dev_alloc_skb(new_len); if (WARN_ONCE(!new, "rx routine starvation\n")) goto next_rp;