CVE-2025-38567: nfsd: avoid ref leak in nfsd_open_local_fh()

Severity: medium (CVSS 4.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-19 · updated 2026-06-17
Weakness: CWE-362

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: avoid ref leak in nfsd_open_local_fh() If two calls to nfsd_open_local_fh() race and both successfully call nfsd_file_acquire_local(), they will both get an extra reference to the net to accompany the file reference stored in *pnf. One of them will fail to store (using xchg()) the file reference in *pnf and will drop that reference but WON'T drop the accompanying reference to the net. This leak means that when the nfs server is shut down it will hang in nfsd_shutdown_net() waiting for &nn->nfsd_net_free_done. This patch adds the missing nfsd_net_put().

Affected products

Linux kernel: from 6.15.3 before 6.15.10; 6.16, 6.17-rc1 — fixed in 6.15.10

How to fix

Upgrade to a fixed version: Linux kernel 6.15.10. Check the vendor advisory for mitigations.

References

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