CVE-2025-38488

What it is

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix use-after-free in crypt_message when using async crypto The CVE-2024-50047 fix removed asynchronous crypto handling from crypt_message(), assuming all crypto operations are synchronous. However, when hardware crypto accelerators are used, this can cause use-after-free crashes: crypt_message() // Allocate the creq buffer containing the req creq = smb2_get_aead_req(..., &req); // Async encryption returns -EINPROGRESS immediately rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req); // Free creq while async operation is still in progress kvfree_sensitive(creq, ...); Hardware crypto modules often implement async AEAD operations for performance. When crypto_aead_encrypt/decrypt() returns -EINPROGRESS, the operation completes asynchronously. Without crypto_wait_req(), the function immediately frees the request buffer, leading to crashes when the driver later accesses the freed memory. This results in a use-after-free condition when the hardware crypto driver later accesses the freed request structure, leading to kernel crashes with NULL pointer dereferences. The issue occurs because crypto_alloc_aead() with mask=0 doesn't guarantee synchronous operation. Even without CRYPTO_ALG_ASYNC in the mask, async implementations can be selected. Fix by restoring the async crypto handling: - DECLARE_CRYPTO_WAIT(wait) for completion tracking - aead_request_set_callback() for async completion notification - crypto_wait_req() to wait for operation completion This ensures the request buffer isn't freed until the crypto operation completes, whether synchronous or asynchronous, while preserving the CVE-2024-50047 fix.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.8% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2025-07-28 12:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-30 06:23 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.8% in the next 30 days (EPSS).
• Severity: 9.8 CRITICAL (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2025-07-28 12:15 UTC

Last modified

2026-07-30 06:23 UTC

Exploit probability

0.8% · EPSS, next 30 days

Weakness

CWE-416 · Use after free

Record status

Modified

Affected

• Linux Kernel < 5.10.241
• Linux Kernel < 5.15.190
• Linux Kernel < 6.1.147
• Linux Kernel < 6.6.100
• Linux Kernel < 6.12.40
• Linux Kernel < 6.15.8
• Linux Kernel 6.16
• Debian Linux 11.0

Attack profile CVSS 3.1 · 9.8

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2025-38488.md and follow it. Check whether this project is affected by CVE-2025-38488. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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