CVE-2022-49326: rtl818x: Prevent using not initialized queues

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-26 · updated 2026-06-17
Weakness: CWE-908

Description

In the Linux kernel, the following vulnerability has been resolved: rtl818x: Prevent using not initialized queues Using not existing queues can panic the kernel with rtl8180/rtl8185 cards. Ignore the skb priority for those cards, they only have one tx queue. Pierre Asselin (pa@panix.com) reported the kernel crash in the Gentoo forum: https://forums.gentoo.org/viewtopic-t-1147832-postdays-0-postorder-asc-start-25.html He also confirmed that this patch fixes the issue. In summary this happened: After updating wpa_supplicant from 2.9 to 2.10 the kernel crashed with a "divide error: 0000" when connecting to an AP. Control port tx now tries to use IEEE80211_AC_VO for the priority, which wpa_supplicants starts to use in 2.10. Since only the rtl8187se part of the driver supports QoS, the priority of the skb is set to IEEE80211_AC_BE (2) by mac80211 for rtl8180/rtl8185 cards. rtl8180 is then unconditionally reading out the priority and finally crashes on drivers/net/wireless/realtek/rtl818x/rtl8180/dev.c line 544 without this patch: idx = (ring->idx + skb_queue_len(&ring->queue)) % ring->entries "ring->entries" is zero for rtl8180/rtl8185 cards, tx_ring[2] never got initialized.

Affected products

Linux kernel: before 4.9.318; from 4.10 before 4.14.283; from 4.15 before 4.19.247; from 4.20 before 5.4.198; from 5.5 before 5.10.121; from 5.11 before 5.15.46 — fixed in 4.14.283, 4.19.247, 4.9.318, 5.10.121, 5.15.46, 5.17.14

How to fix

Upgrade to a fixed version: Linux kernel 4.14.283, 4.19.247, 4.9.318, 5.10.121. Check the vendor advisory for mitigations.

References

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