Описание
In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7996: fix TX DMA mapping leak for AddBA req frames
mt7996/mt7992 hand the firmware a HW MAC-TXP for AddBA req action frames
(MT_TXD7_MAC_TXD, set in mt7996_mac_write_txwi_80211()), but are otherwise
FW-TXP devices. On tx free mt76_connac_txp_skb_unmap() therefore decodes
the per-frame txp as a struct mt76_connac_fw_txp. For a MAC-TXP the
fw_txp.nbuf byte aliases the AddBA TID word (MT_TXP1_TID_ADDBA), which is
always zero, so the unmap loop runs zero times and the skb DMA mapping in
buf[1] is never unmapped. buf[1].skip_unmap is set unconditionally, so the
generic DMA-ring cleanup skips it as well.
Each AddBA req therefore leaks one TX DMA mapping, roughly one per
(re)association. With WED enabled these mappings are bounced through the
WED swiotlb pool, so under continuous client reconnect churn the pool is
exhausted after ~1-2 days, after which DMA mapping fails for WED, the WiFi
MCU and other on-SoC consumers.
Keep the deferred (token release) unmap that the design relies on, and add
an mt7996-specific txp unmap that inspects MT_TXD7_MAC_TXD and unmaps
buf[1] from the MAC-TXP layout for those frames, delegating to
mt76_connac_txp_skb_unmap() otherwise.
A flaw was found in the Linux kernel's mt76: mt7996 Wi-Fi driver. The driver incorrectly manages Direct Memory Access (DMA) mappings when processing AddBA request frames, causing a continuous leak of these mappings. Over time, this resource exhaustion can lead to a Denial of Service (DoS) for the Wi-Fi functionality and other integrated components.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | ||
| Red Hat Enterprise Linux 10 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7996: fix TX DMA mapping leak for AddBA req frames mt7996/mt7992 hand the firmware a HW MAC-TXP for AddBA req action frames (MT_TXD7_MAC_TXD, set in mt7996_mac_write_txwi_80211()), but are otherwise FW-TXP devices. On tx free mt76_connac_txp_skb_unmap() therefore decodes the per-frame txp as a struct mt76_connac_fw_txp. For a MAC-TXP the fw_txp.nbuf byte aliases the AddBA TID word (MT_TXP1_TID_ADDBA), which is always zero, so the unmap loop runs zero times and the skb DMA mapping in buf[1] is never unmapped. buf[1].skip_unmap is set unconditionally, so the generic DMA-ring cleanup skips it as well. Each AddBA req therefore leaks one TX DMA mapping, roughly one per (re)association. With WED enabled these mappings are bounced through the WED swiotlb pool, so under continuous client reconnect churn the pool is exhausted after ~1-2 days, after which DMA mapping fails for WED, the WiFi MCU and other on-SoC ...
In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7996: fix TX DMA mapping leak for AddBA req frames mt7996/mt7992 hand the firmware a HW MAC-TXP for AddBA req action frames (MT_TXD7_MAC_TXD, set in mt7996_mac_write_txwi_80211()), but are otherwise FW-TXP devices. On tx free mt76_connac_txp_skb_unmap() therefore decodes the per-frame txp as a struct mt76_connac_fw_txp. For a MAC-TXP the fw_txp.nbuf byte aliases the AddBA TID word (MT_TXP1_TID_ADDBA), which is always zero, so the unmap loop runs zero times and the skb DMA mapping in buf[1] is never unmapped. buf[1].skip_unmap is set unconditionally, so the generic DMA-ring cleanup skips it as well. Each AddBA req therefore leaks one TX DMA mapping, roughly one per (re)association. With WED enabled these mappings are bounced through the WED swiotlb pool, so under continuous client reconnect churn the pool is exhausted after ~1-2 days, after which DMA mapping fails for WED, the WiFi MCU and other on-SoC
In the Linux kernel, the following vulnerability has been resolved: w ...
In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7996: fix TX DMA mapping leak for AddBA req frames mt7996/mt7992 hand the firmware a HW MAC-TXP for AddBA req action frames (MT_TXD7_MAC_TXD, set in mt7996_mac_write_txwi_80211()), but are otherwise FW-TXP devices. On tx free mt76_connac_txp_skb_unmap() therefore decodes the per-frame txp as a struct mt76_connac_fw_txp. For a MAC-TXP the fw_txp.nbuf byte aliases the AddBA TID word (MT_TXP1_TID_ADDBA), which is always zero, so the unmap loop runs zero times and the skb DMA mapping in buf[1] is never unmapped. buf[1].skip_unmap is set unconditionally, so the generic DMA-ring cleanup skips it as well. Each AddBA req therefore leaks one TX DMA mapping, roughly one per (re)association. With WED enabled these mappings are bounced through the WED swiotlb pool, so under continuous client reconnect churn the pool is exhausted after ~1-2 days, after which DMA mapping fails for WED, the WiFi MCU and other on-S...
EPSS
5.5 Medium
CVSS3