UBUNTU-CVE-2026-89566: Medium severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: jbd2: check needresched() when skipping busy checkpoint buffers journalshrinkonecplist() skips busy checkpoint buffers when called with JBD2SHRINKBUSYSKIP. The continue statement on this path also skips the needresched() check at the end of the loop body. Consequently, when a checkpoint list contains mostly busy buffers, the shrinker can walk the entire list while holding journal->jlistlock, even when a reschedule has been requested. Large checkpoint lists under memory pressure can therefore cause long lock hold times and leave other CPUs spinning on jlistlock, resulting in soft lockups or RCU stalls. Route the busy-buffer path through the needresched() check so that the shrinker can release jlistlock and reschedule promptly, restoring parity with the clean-buffer path, which already checks needresched(). This does not change which checkpoint buffers are eligible for removal.
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
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1