CVE-2024-38605
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.75%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.75% probability · 53th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-476
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/39381fe7394e5eafac76e7e9367e7351138a29c1Patch
- https://git.kernel.org/stable/c/6b8374ee2cabcf034faa34e69a855dc496a9ec12Patch
- https://git.kernel.org/stable/c/c935e72139e6d523defd60fe875c01eb1f9ea5c5Patch
- https://git.kernel.org/stable/c/d7ff29a429b56f04783152ad7bbd7233b740e434Patch
- https://git.kernel.org/stable/c/e007476725730c1a68387b54b7629486d8a8301ePatch
- https://git.kernel.org/stable/c/e644036a3e2b2c9b3eee3c61b5d31c2ca8b5ba92Patch
- https://git.kernel.org/stable/c/e7e0ca200772bdb2fdc6d43d32d341e87a36f811Patch
- https://git.kernel.org/stable/c/39381fe7394e5eafac76e7e9367e7351138a29c1Patch
- https://git.kernel.org/stable/c/6b8374ee2cabcf034faa34e69a855dc496a9ec12Patch
- https://git.kernel.org/stable/c/c935e72139e6d523defd60fe875c01eb1f9ea5c5Patch
- https://git.kernel.org/stable/c/d7ff29a429b56f04783152ad7bbd7233b740e434Patch
- https://git.kernel.org/stable/c/e007476725730c1a68387b54b7629486d8a8301ePatch
- https://git.kernel.org/stable/c/e644036a3e2b2c9b3eee3c61b5d31c2ca8b5ba92Patch
- https://git.kernel.org/stable/c/e7e0ca200772bdb2fdc6d43d32d341e87a36f811Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.