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.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
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Sun, 18 Oct 2026 20:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-125 |
Sun, 18 Oct 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | wifi: mac80211: fix slab-out-of-bounds read in ieee80211_monitor_select_queue() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-18T15:48:56.733Z
Reserved: 2026-09-25T10:25:14.371Z
Link: CVE-2026-98810
No data.
Status : Received
Published: 2026-10-18T16:17:35.103
Modified: 2026-10-18T16:17:35.103
Link: CVE-2026-98810
No data.
OpenCVE Enrichment
Updated: 2026-10-18T20:30:17Z
-
CWE-125
Out-of-bounds Read