Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

llc: reserve device headroom for allocated frames

llc_alloc_frame() reserves link-layer headroom using the device type. This is insufficient for stacked Ethernet devices such as VLAN devices, where vlan_dev_hard_header() pushes a VLAN header before the lower device's Ethernet header. An LLC response on such a device can therefore underflow skb headroom in eth_header().

Use LL_RESERVED_SPACE() to account for the device's actual required headroom while preserving the existing LLC device-type check.