CVE-2026-80935: wifi: mt76: mt7996: bound the device EEPROM address before the EFUSE copy
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7996: bound the device EEPROM address before the EFUSE copy
mt7996mcugeteeprom() derives the destination of the EFUSE/EXT block copy from the address reported by the MCU response (event->addr, a device-controlled le32) and clamps only the copy length, never the destination offset into dev->mt76.eeprom.data. A malicious or malfunctioning device can report an arbitrary address and drive an out-of-bounds write of up to MT7996EXTEEPROMBLOCKSIZE bytes past eeprom.data.
Reject a response whose address would place the copy outside eeprom.data before deriving the destination pointer. Devices that echo the requested in-bounds offset are unaffected.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Update mt7996_mcu_get_eeprom() to reject any MCU response whose address would place the copy outside eeprom.data (clamp/validate the device-controlled offset before deriving the destination pointer), preventing out-of-bounds writes of up to MT7996_EXT_EEPROM_BLOCK_SIZE bytes.
mt76 mt7996 (mt7996_mcu_get_eeprom) EFUSE/EXT block destination bounds check = enabled
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Systems using the Linux kernel mt76 mt7996 Wi-Fi driver are exposed when the device returns an EEPROM response with an address outside the EEPROM data buffer. Devices that echo the requested in-bounds offset are unaffected.
What must occur for exploitation or triggering?
A malicious or malfunctioning device must report an arbitrary address in an MCU EEPROM response. That address is used as the destination offset for an EFUSE/EXT block copy, which can cause an out-of-bounds write of up to MT7996_EXT_EEPROM_BLOCK_SIZE bytes past eeprom.data.
How can I tell whether a device is affected?
The relevant behavior is whether the device returns the requested, in-bounds EEPROM offset in its MCU response. Devices that echo that requested offset are not affected; devices capable of returning an out-of-bounds address can trigger the issue.