Описание
In the Linux kernel, the following vulnerability has been resolved:
ALSA: ctxfi: Fix potential OOB access in audio mixer handling
In the audio mixer handling code of ctxfi driver, the conf field is
used as a kind of loop index, and it's referred in the index callbacks
(amixer_index() and sum_index()).
As spotted recently by fuzzers, the current code causes OOB access at
those functions.
| UBSAN: array-index-out-of-bounds in /build/reproducible-path/linux-6.17.8/sound/pci/ctxfi/ctamixer.c:347:48
| index 8 is out of range for type 'unsigned char [8]'
After the analysis, the cause was found to be the lack of the proper
(re-)initialization of conj field.
This patch addresses those OOB accesses by adding the proper
initializations of the loop indices.
A flaw was found in the Linux kernel's ALSA (Advanced Linux Sound Architecture) ctxfi driver. A local user with access to the sound device and ALSA control interfaces can exploit this out-of-bounds memory access vulnerability by exercising mixer controls. This issue stems from the improper re-initialization of a loop index field, which can cause the system to access memory outside of its allocated bounds. Successful exploitation can lead to a kernel crash or unstable system behavior, resulting in a Denial of Service (DoS).
Отчет
An out of bounds access can occur in the ALSA ctxfi mixer code because the rsc.conj field is used as a loop index in amixer_index and sum_index. The driver did not reliably reinitialize conj when setting up amixer and sum resources. If conj retains a stale value, the index callbacks can use it to access fixed size arrays out of range, which was observed by fuzzers and reported by UBSAN as an array index out of bounds. The issue is reachable through normal mixer control handling once the ctxfi driver is loaded. A local user with access to the sound device and ALSA control interfaces can trigger the relevant paths by exercising mixer controls. For the CVSS the PR is L because access to ALSA control devices is typically mediated by local permissions and group membership. The primary impact is availability because an out of bounds access in kernel space can crash the kernel or lead to unstable behavior.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Affected | ||
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel | Affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Affected | ||
| Red Hat Enterprise Linux 8 | kernel | Affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Affected | ||
| Red Hat Enterprise Linux 9 | kernel | Affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Affected |
Показывать по
Дополнительная информация
Статус:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: ALSA: ctxfi: Fix potential OOB access in audio mixer handling In the audio mixer handling code of ctxfi driver, the conf field is used as a kind of loop index, and it's referred in the index callbacks (amixer_index() and sum_index()). As spotted recently by fuzzers, the current code causes OOB access at those functions. | UBSAN: array-index-out-of-bounds in /build/reproducible-path/linux-6.17.8/sound/pci/ctxfi/ctamixer.c:347:48 | index 8 is out of range for type 'unsigned char [8]' After the analysis, the cause was found to be the lack of the proper (re-)initialization of conj field. This patch addresses those OOB accesses by adding the proper initializations of the loop indices.
In the Linux kernel, the following vulnerability has been resolved: ALSA: ctxfi: Fix potential OOB access in audio mixer handling In the audio mixer handling code of ctxfi driver, the conf field is used as a kind of loop index, and it's referred in the index callbacks (amixer_index() and sum_index()). As spotted recently by fuzzers, the current code causes OOB access at those functions. | UBSAN: array-index-out-of-bounds in /build/reproducible-path/linux-6.17.8/sound/pci/ctxfi/ctamixer.c:347:48 | index 8 is out of range for type 'unsigned char [8]' After the analysis, the cause was found to be the lack of the proper (re-)initialization of conj field. This patch addresses those OOB accesses by adding the proper initializations of the loop indices.
In the Linux kernel, the following vulnerability has been resolved: A ...
In the Linux kernel, the following vulnerability has been resolved: ALSA: ctxfi: Fix potential OOB access in audio mixer handling In the audio mixer handling code of ctxfi driver, the conf field is used as a kind of loop index, and it's referred in the index callbacks (amixer_index() and sum_index()). As spotted recently by fuzzers, the current code causes OOB access at those functions. | UBSAN: array-index-out-of-bounds in /build/reproducible-path/linux-6.17.8/sound/pci/ctxfi/ctamixer.c:347:48 | index 8 is out of range for type 'unsigned char [8]' After the analysis, the cause was found to be the lack of the proper (re-)initialization of conj field. This patch addresses those OOB accesses by adding the proper initializations of the loop indices.
ELSA-2026-50145: Unbreakable Enterprise kernel security update (IMPORTANT)
5.5 Medium
CVSS3