CVE-2024-38605

ALSA: core: Fix NULL module pointer assignment at card init

Published Jun 19, 2024 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

ALSA: core: Fix NULL module pointer assignment at card init

The commit 81033c6b584b ("ALSA: core: Warn on empty module")
introduced a WARN_ON() for a NULL module pointer passed at snd_card
object creation, and it also wraps the code around it with '#ifdef
MODULE'. This works in most cases, but the devils are always in
details. "MODULE" is defined when the target code (i.e. the sound
core) is built as a module; but this doesn't mean that the caller is
also built-in or not. Namely, when only the sound core is built-in
(CONFIG_SND=y) while the driver is a module (CONFIG_SND_USB_AUDIO=m),
the passed module pointer is ignored even if it's non-NULL, and
card->module remains as NULL. This would result in the missing module
reference up/down at the device open/close, leading to a race with the
code execution after the module removal.

For addressing the bug, move the assignment of card->module again out
of ifdef. The WARN_ON() is still wrapped with ifdef because the
module can be really NULL when all sound drivers are built-in.

Note that we keep 'ifdef MODULE' for WARN_ON(), otherwise it would
lead to a false-positive NULL module check. Admittedly it won't catch
perfectly, i.e. no check is performed when CONFIG_SND=y. But, it's no
real problem as it's only for debugging, and the condition is pretty
rare.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-5730-1 linux security update
Ubuntu USN Ubuntu USN USN-6949-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6949-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6952-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6955-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7007-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7007-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7007-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7009-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7009-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7019-1 Linux kernel vulnerabilities
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Aug 5, 2026, 11:33 AM
Reserved
Jun 18, 2024, 7:36 PM
Status
Modified
Published
Jun 19, 2024, 2:15 PM
Modified
Aug 4, 2026, 11:18 AM
Severity
Low
Public date
Jun 19, 2024, 12:00 AM