UBUNTU-CVE-2026-72368: High severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: cachefiles: Fix double unlock in nomemdalloc error path When startcreating() fails and returns -ENOMEM, it has already released the parent directory lock in startdirop(): static struct dentry startdirop(...) { ... inodelocknested(dir, IMUTEXPARENT); dentry = lookuponeqstrexcl(name, parent, lookupflags); if (ISERR(dentry)) inodeunlock(dir); <-- Lock released on error return dentry; } However, the nomemdalloc error path in cachefilesgetdirectory() unconditionally calls inodeunlock(dinode(dir)) again, causing a double unlock that corrupts the rwsem state. This is a leftover from commit 7ab96df840e60 which replaced manual locking with startcreating() but failed to update the nomemdalloc path (while correctly updating mkdirerror and lookuperror paths).
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
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ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - 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 7.0.0-1014.14~24.04.1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38~24.04.4 - 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 7.0.0-1013.13~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-38.38 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - 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 7.0.0-1014.14 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1008.9 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1015.15 - 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 7.0.0-1015.15 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-38.38.1
Event History
Frequently Asked Questions
What conditions are required to trigger the double unlock?
The error path is reached when start_creating() fails with -ENOMEM while cachefiles_get_directory() is handling directory creation. The affected path then unlocks the parent directory inode a second time after __start_dirop() has already released that lock.
What is the practical impact of a successful trigger?
The second inode_unlock() corrupts the rwsem state. The provided severity vector rates the issue high, with high confidentiality, integrity, and availability impact, and requires local access and low privileges.
Which Ubuntu kernel package families are identified as affected?
The listed packages are ubuntu/linux-riscv, ubuntu/linux-realtime, ubuntu/linux-hwe-edge, ubuntu/linux-azure, ubuntu/linux-gcp, ubuntu/linux-azure-fde, ubuntu/linux-gke, and ubuntu/linux-aws-5.0.