CVE-2026-74648: staging: rtl8723bs: validate monitor transmit frame lengths
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: validate monitor transmit frame lengths
rtwcfg80211monitorifxmitentry() 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Update the Linux kernel driver logic (staging: rtl8723bs: validate monitor transmit frame lengths) so it rejects monitor transmit frames that do not contain the complete base 802.11 header/data and does not remove the radiotap header/span until the skb is confirmed to contain them.
rtw_cfg80211_monitor_if_xmit_entry() / rtl8723bs staging monitor transmit frame validation = validate monitor transmit frame lengths; confirm skb contains base 802.11 header before reading 802.11 frame control field
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Exposure is limited to Linux kernel systems using the rtl8723bs driver’s monitor-interface transmit path. The vulnerable processing occurs when that path handles transmitted frames after removing a radiotap header.
What does an attacker need to supply to trigger the flaw?
The attacker needs to cause a truncated monitor-mode transmit frame to be processed. In particular, the frame can lack a complete base 802.11 header or, for data frames, the full calculated 802.11, QoS, and SNAP header span.