CVE-2025-38411: netfs: Fix double put of request

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-25 · updated 2026-07-30
Weakness: CWE-415

Description

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix double put of request If a netfs request finishes during the pause loop, it will have the ref that belongs to the IN_PROGRESS flag removed at that point - however, if it then goes to the final wait loop, that will *also* put the ref because it sees that the IN_PROGRESS flag is clear and incorrectly assumes that this happened when it called the collector. In fact, since IN_PROGRESS is clear, we shouldn't call the collector again since it's done all the cleanup, such as calling ->ki_complete(). Fix this by making netfs_collect_in_app() just return, indicating that we're done if IN_PROGRESS is removed.

Affected products

Linux kernel: from 6.15.3 before 6.15.6; 6.16-rc1, 6.16-rc2, 6.16-rc3, 6.16-rc4 — fixed in 6.15.6

How to fix

Upgrade to a fixed version: Linux kernel 6.15.6. Check the vendor advisory for mitigations.

References

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