UBUNTU-CVE-2026-97516: Medium severity ubuntu/linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: wifi: rtw88: Add NULL check for chip->edccath in rtwfwadaptivityresult() It was recently reported that rtwfwadaptivityresult() in fw.c dereferences rtwdev->chip->edccath without a NULL check. The issue is that devices with the 8821CE chip don't define edccath in their chip info. As a result, when rtwfwadaptivityresult() tries to dereference it, the kernel triggers an oops. Add a NULL check for edccath before dereferencing it in rtwfwadaptivityresult() in fw.c. Placing the check at the function entry avoids logging any garbage values. This change does not address the root cause for this behavior, but it prevents the NULL dereference and the resulting oops while a more permanent solution is developed. Tested on a 8822CE chip which defines edccath, so this issue is not present on it, but it still uses this driver and I can verify there are no regressions.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1 - Compensating control
Add a NULL check for chip->edcca_th at the entry of rtw_fw_adaptivity_result() in fw.c, before dereferencing it, to prevent the NULL dereference and resulting kernel oops on devices such as the 8821CE.
Event History
Frequently Asked Questions
Which systems are most likely to be exposed?
Systems using the rtw88 wireless driver with an 8821CE chip are affected because that chip does not define edcca_th in its chip information. The issue was not observed on the tested 8822CE chip, which defines edcca_th.
What level of access does an attacker need?
The supplied CVSS vector indicates local access and low privileges are required. No user interaction is required.
What is the practical impact of successful exploitation?
Dereferencing the missing value causes a kernel oops, creating an availability impact. The supplied CVSS vector rates availability impact as high and does not indicate confidentiality or integrity impact.