Kernel crash via unlocked NFS dentry dereference
Published Dec 16, 2025 · Updated Dec 16, 2025
Race condition in the Linux kernel NFSv4 client allows attackers to crash the kernel via concurrent directory operations. nfs4_setup_readdir() reads d_parent->d_inode while another operation can move the dentry, and xdr_encode_hyper() dereferences that inode outside d_lock. Triggering the oops requires winning a narrow race during NFSv4 readdir processing; the kernel maintainer states that real hardware is unlikely to hit it and KVM may make it more feasible.
Summary
What happened
Race condition in the Linux kernel NFSv4 client allows attackers to crash the kernel via concurrent directory operations. nfs4_setup_readdir() reads d_parent->d_inode while another operation can move the dentry, and xdr_encode_hyper() dereferences that inode outside d_lock. Triggering the oops requires winning a narrow race during NFSv4 readdir processing; the kernel maintainer states that real hardware is unlikely to hit it and KVM may make it more feasible.
The record
- CVE
- CVE-2025-68185
- Published
- Dec 16, 2025
- Updated
- Dec 16, 2025
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Dec 16, 2025CVE publishedPublication date reported by the CVE source.
- Dec 16, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <40be5b9080114f18b0cea386db415b68a7273c1a
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <504b3fb9948a9e96ebbabdee0d33966a8bab15cb
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6025f641a0e30afdc5aa62017397b1860ad9f677
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a890a2e339b929dbd843328f9a92a1625404fe63
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e6cafe71eb3b5579b245ba1bd528a181e77f3df1
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <eacfd08b26a062f1095b18719715bc82ad35312e
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f5e570eaab36a110c6ffda32b87c51170990c2d1
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fa4daf7d11e45b72aad5d943a7ab991f869fff79
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
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Public exploit references
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Technologies
Your stack
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Your stack
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