CVE-2025-38488

A flaw was found in the Linux kernel's Server Message Block (SMB) client. A local attacker can exploit this use-after-free vulnerability by triggering asynchronous crypto operations in the crypt_message() function. This occurs because a memory buffer is prematurely freed while an asynchronous cryptographic operation is still in progress. Successful exploitation leads to kernel crashes, resulting in a Denial of Service (DoS).

A MODERATE severity use-after-free flaw was found in the Linux kernel SMB client in Red Hat Enterprise Linux 9 and 10. When encrypting or decrypting an SMB message, crypt_message() frees the request buffer as soon as crypto_aead_encrypt()/crypto_aead_decrypt() returns -EINPROGRESS, but crypto implementations such as hardware crypto accelerators may complete the operation asynchronously and access that memory afterwards. A local attacker who can trigger encrypted SMB traffic on a system whose crypto driver handles AEAD operations asynchronously can exploit this premature free to crash the kernel, resulting in a denial of service. Red Hat Enterprise Linux 6, 7, and 8, and Red Hat In-Vehicle OS are not affected because the vulnerable code is not present in those releases. Red Hat rates this flaw Moderate because exploitation requires local access and the impact is limited to availability (kernel crash), with no direct impact on confidentiality or integrity; this differs from the NIST CVSS 3.1 score of 7.8, which assumes high confidentiality, integrity, and availability impact.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.