CVE-2025-38488

Advisory lineage Upstream: 0 Downstream: 119
Analyzed
Published: 28 Jul 2025, 11:21
Last modified:23 May 2026, 15:59

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (nvd)
EPSS Score
0.04% LOW
0% probability +0.03%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

28 Jul 2025, 11:21
Published
Vulnerability first disclosed
23 May 2026, 15:59
Last Modified
Vulnerability information updated

Description

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.

CVSS Metrics

  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.04%• Percentile: 12%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • debian•debian_linux

    11.0

  • linux•linux

    ≥ 8f14a476abba13144df5434871a7225fd29af633, < 5d047b12f86cc3b9fde1171c02d9bccf4dba0632 | ≥ ef51c0d544b1518b35364480317ab6d3468f205d, < 6550b2bef095d0dd2d2c8390d2ea4c3837028833 | ≥ bce966530fd5542bbb422cb45ecb775f7a1a6bc3, < 9a1d3e8d40f151c2d5a5f40c410e6e433f62f438 | ≥ 0809fb86ad13b29e1d6d491364fc7ea4fb545995, < 15a0a5de49507062bc3be4014a403d8cea5533de | ≥ b0abcd65ec545701b8793e12bc27dc98042b151a, < 2a76bc2b24ed889a689fb1c9015307bf16aafb5b | ≥ b0abcd65ec545701b8793e12bc27dc98042b151a, < 8ac90f6824fc44d2e55a82503ddfc95defb19ae0 | ≥ b0abcd65ec545701b8793e12bc27dc98042b151a, < b220bed63330c0e1733dc06ea8e75d5b9962b6b6 | 538c26d9bf70c90edc460d18c81008a4e555925a | ≥ 5.10.237, < 5.10.241 | ≥ 5.15.181, < 5.15.190 | ≥ 6.1.128, < 6.1.147 | ≥ 6.6.57, < 6.6.100 | ≥ 6.11.4, < 6.12 | 6.12

  • linux•linux_kernel

    ≥ 5.10.237, < 5.10.241 | ≥ 5.15.181, < 5.15.190 | ≥ 6.1.128, < 6.1.147 | ≥ 6.6.57, < 6.6.100 | ≥ 6.11.4, < 6.12.40 | ≥ 6.13, < 6.15.8 | 6.16:rc1 | 6.16:rc2 | 6.16:rc3 | 6.16:rc4 | 6.16:rc5 | 6.16:rc6

References (9)