wifi: mac80211: fix slab-out-of-bounds read in ieee80211_monitor_select_queue()

Summary

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix slab-out-of-bounds read in ieee80211_monitor_select_queue() ieee80211_monitor_select_queue() validates the skb length using skb->len before dereferencing pointers into skb->data to access the 802.11 header. However, skb->len includes data in both the linear head buffer and non-linear fragments/pages. When AF_PACKET sends a packet large enough to become non-linear, the 802.11 header at skb->data + len_rthdr may extend past the linear head buffer even though skb->len appears sufficient. This leads to a slab-out-of-bounds read when accessing hdr->frame_control, as the kernel reads beyond the allocated skb head buffer: BUG: KASAN: slab-out-of-bounds in ieee80211_monitor_select_queue+0x1ed/0x220 syzbot has hit the same issues. Fix this by checking skb_headlen(skb) (which gives the length of the linear data region) instead of skb->len before dereferencing skb->data pointers. This ensures the required bytes are actually present in the linear portion of the skb. Apply the same fix to ieee80211_validate_radiotap_len() which has the same class of bug: it uses skb->len to validate accesses to skb->data, and to the corresponding checks in ieee80211_monitor_start_xmit(): for drivers advertising NETIF_F_SG the skb is not linearized before ndo_start_xmit, so the 802.11 header can be read past the linear buffer there as well.

Timeline

1. Oct 18, 2026, 3:48 PM UTCCVE published
2. Oct 19, 2026, 9:26 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 9b8a74e3482f9fc077a88c13fa0ceca8feb0b772 · fixed in 63e7064b4c1c4b540bf2f0cba47384f92ab95307; From 9b8a74e3482f9fc077a88c13fa0ceca8feb0b772 · fixed in 6f63e919fe1e335b8abcb3a28bfd4804a98d875a

• Linux Linux

  2.6.24

• KernelLinux

  From 2.6.24 · fixed in 7.2.10

References 2