In the Linux kernel, the following vulnerability has been resolved: ALSA: oss: Fix PCM OSS buffer allocation overflow We've got syzbot reports hitting INT_MAX overflow at vmalloc() allocation that is called from snd_pcm_plug_alloc(). Although we apply the restrictions to input parameters, it's based only on the hw_params of the underlying PCM device. Since the PCM OSS layer allocates a temporary buffer for the data conversion, the size may become unexpectedly large when more channels or higher rates is given; in the reported case, it went over INT_MAX, hence it hits WARN_ON(). This patch is an attempt to avoid such an overflow and an allocation for too large buffers. First off, it adds the limit of 1MB as the upper bound for period bytes. This must be large enough for all use cases, and we really don't want to handle a larger temporary buffer than this size. The size check is performed at two places, where the original period bytes is calculated and where the plugin buffer size is calculated. In addition, the driver uses array_size() and array3_size() for multiplications to catch overflows for the converted period size and buffer bytes.
History

Fri, 28 Feb 2025 01:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Wed, 26 Feb 2025 02:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: ALSA: oss: Fix PCM OSS buffer allocation overflow We've got syzbot reports hitting INT_MAX overflow at vmalloc() allocation that is called from snd_pcm_plug_alloc(). Although we apply the restrictions to input parameters, it's based only on the hw_params of the underlying PCM device. Since the PCM OSS layer allocates a temporary buffer for the data conversion, the size may become unexpectedly large when more channels or higher rates is given; in the reported case, it went over INT_MAX, hence it hits WARN_ON(). This patch is an attempt to avoid such an overflow and an allocation for too large buffers. First off, it adds the limit of 1MB as the upper bound for period bytes. This must be large enough for all use cases, and we really don't want to handle a larger temporary buffer than this size. The size check is performed at two places, where the original period bytes is calculated and where the plugin buffer size is calculated. In addition, the driver uses array_size() and array3_size() for multiplications to catch overflows for the converted period size and buffer bytes.
Title ALSA: oss: Fix PCM OSS buffer allocation overflow
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-02-26T01:56:28.552Z

Updated: 2025-05-04T08:34:23.499Z

Reserved: 2025-02-26T01:49:39.302Z

Link: CVE-2022-49292

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-02-26T07:01:06.047

Modified: 2025-02-26T07:01:06.047

Link: CVE-2022-49292

cve-icon Redhat

Severity : Low

Publid Date: 2025-02-26T00:00:00Z

Links: CVE-2022-49292 - Bugzilla