CVE-2025-37891: linux kernel Buffer Overflow — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: ump: Fix buffer overflow at UMP SysEx message conversion The conversion function from MIDI 1.0 to UMP packet contains an internal buffer to keep the incoming MIDI bytes, and its size is 4, as it was supposed to be the max size for a MIDI1 UMP packet data. However, the implementation overlooked that SysEx is handled in a different format, and it can be up to 6 bytes, as found in do_convert_to_ump(). It leads eventually to a buffer overflow, and may corrupt the memory when a longer SysEx message is received. The fix is simply to extend the buffer size to 6 to fit with the SysEx UMP message.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-120 CWE-120

Affected Products

Vendor	Product	Versions
linux	linux_kernel	6.5 — 6.6.90
linux	linux_kernel	6.7 — 6.12.28
linux	linux_kernel	6.13 — 6.14.6
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/226beac5605afbb33f8782148d188b64396145a4 https://git.kernel.org/stable/c/42ef48dd4ebb082a1a90b5c3feeda2e68a9e32fe https://git.kernel.org/stable/c/56f1f30e6795b890463d9b20b11e576adf5a2f77 https://git.kernel.org/stable/c/ce4f77bef276e7d2eb7ab03a5d08bcbaa40710ec

Frequently Asked Questions

What is CVE-2025-37891? +

In the Linux kernel, the following vulnerability has been resolved: ALSA: ump: Fix buffer overflow at UMP SysEx message conversion The conversion function from MIDI 1.0 to UMP packet contains an internal buffer to keep the incoming MIDI bytes, and its size is 4, as it was supposed to be the max size for a MIDI1 UMP packet data. However, the implementation overlooked that SysEx is handled in a different format, and it can be up to 6 bytes, as found in do_convert_to_ump(). It leads eventually to a buffer overflow, and may corrupt the memory when a longer SysEx message is received. The fix is simply to extend the buffer size to 6 to fit with the SysEx UMP message. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2025-37891? +

CVE-2025-37891 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-37891? +

CVE-2025-37891 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-37891? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2025-37891