CVE-2026-72220: sunrpc: harden rq_procinfo lifecycle to prevent double-free
In the Linux kernel, the following vulnerability has been resolved:
sunrpc: harden rqprocinfo lifecycle to prevent double-free
The svcreleaserqst() function executes the callback inside rqstp->rqprocinfo->pcrelease. However, if a worker thread begins processing a new request and encounters an early error path (e.g., unsupported protocol, short frame, or bad auth) before a valid rqprocinfo is installed, a stale release hook can be re-triggered against reused state from the previous RPC, resulting in a double-free or use-after-free vulnerability.
Harden the lifecycle of rqprocinfo by: 1. Ensuring svcreleaserqst() always clears rqprocinfo after the optional pcrelease() call, regardless of whether the hook exists. 2. Explicitly clearing rqprocinfo at request entry in svcprocess() before any early decode or drop paths. 3. Ensuring svcprocessbc() does the same at backchannel entry.
This guarantees that error flows will not encounter a non-NULL stale rqprocinfo pointer when there is nothing to release.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
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ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17~24.04.1 - Upgrade
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ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.16~24.04.1 - Upgrade
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ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-34.34~24.04.1 - Upgrade
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ubuntu/linux-nvidia-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1024.25~24.04.1 - Upgrade
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ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1012.12~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-34.34.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-34.34 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1016.16 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1007.8 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-nvidia-bosto a version that resolves this vulnerability.Fixed in 7.0.0-2022.23 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1012.12 - Upgrade
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ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 7.0.0-1020.20 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-34.34.1 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-34.34.1
Event History
Frequently Asked Questions
What is the severity of CVE-2026-72220?
The severity of CVE-2026-72220 is rated at 55.
How does CVE-2026-72220 affect the Linux kernel?
CVE-2026-72220 affects the Linux kernel by introducing a risk of double-free through improper handling of rq_procinfo lifecycle.
What is the nature of the vulnerability in CVE-2026-72220?
CVE-2026-72220 is categorized as a use-after-free vulnerability in the sunrpc component of the Linux kernel.
How can I mitigate CVE-2026-72220 on my system?
To mitigate CVE-2026-72220, ensure that you update to the patched version of the Linux kernel that addresses this vulnerability.
When was CVE-2026-72220 published?
CVE-2026-72220 was published on August 15, 2026.