From: Mariano Baragiola Date: Mon, 27 Jul 2026 16:08:59 +0000 (-0300) Subject: staging: rtl8723bs: validate monitor transmit frame lengths X-Git-Tag: v7.2-rc7~7^2 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=6829665d050983907b560173e49dcc6c11cb2730;p=thirdparty%2Flinux.git staging: rtl8723bs: validate monitor transmit frame lengths rtw_cfg80211_monitor_if_xmit_entry() removes the radiotap header and then reads the 802.11 frame control field without checking that a base 802.11 header remains. The data path also pulls the calculated 802.11, QoS and SNAP header span before confirming that the skb contains it. A truncated frame can therefore cause out-of-bounds reads or leave insufficient data for the Ethernet address writes. Reject frames that do not contain the base 802.11 header and data frames that do not contain their complete calculated header span. Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver") Cc: stable Signed-off-by: Mariano Baragiola Link: https://patch.msgid.link/20260727160859.1917096-1-mbaragiola@linux.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c index 967cd1b34aed..9fa3131feb66 100644 --- a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c +++ b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c @@ -2033,6 +2033,8 @@ static netdev_tx_t rtw_cfg80211_monitor_if_xmit_entry(struct sk_buff *skb, struc /* Skip the ratio tap header */ skb_pull(skb, rtap_len); + if (skb->len < dot11_hdr_len) + goto fail; dot11_hdr = (struct ieee80211_hdr *)skb->data; frame_control = le16_to_cpu(dot11_hdr->frame_control); @@ -2045,6 +2047,8 @@ static netdev_tx_t rtw_cfg80211_monitor_if_xmit_entry(struct sk_buff *skb, struc qos_len = 2; if ((frame_control & 0x0300) == 0x0300) dot11_hdr_len += 6; + if (skb->len < dot11_hdr_len + qos_len + snap_len) + goto fail; memcpy(dst_mac_addr, dot11_hdr->addr1, sizeof(dst_mac_addr)); memcpy(src_mac_addr, dot11_hdr->addr2, sizeof(src_mac_addr));