// For flags

CVE-2024-26654

ALSA: sh: aica: reorder cleanup operations to avoid UAF bugs

Severity Score

"-"
*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

In the Linux kernel, the following vulnerability has been resolved:

ALSA: sh: aica: reorder cleanup operations to avoid UAF bugs

The dreamcastcard->timer could schedule the spu_dma_work and the
spu_dma_work could also arm the dreamcastcard->timer.

When the snd_pcm_substream is closing, the aica_channel will be
deallocated. But it could still be dereferenced in the worker
thread. The reason is that del_timer() will return directly
regardless of whether the timer handler is running or not and
the worker could be rescheduled in the timer handler. As a result,
the UAF bug will happen. The racy situation is shown below:

(Thread 1) | (Thread 2)
snd_aicapcm_pcm_close() |
... | run_spu_dma() //worker
| mod_timer()
flush_work() |
del_timer() | aica_period_elapsed() //timer
kfree(dreamcastcard->channel) | schedule_work()
| run_spu_dma() //worker
... | dreamcastcard->channel-> //USE

In order to mitigate this bug and other possible corner cases,
call mod_timer() conditionally in run_spu_dma(), then implement
PCM sync_stop op to cancel both the timer and worker. The sync_stop
op will be called from PCM core appropriately when needed.

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ALSA: sh: aica: reordenar operaciones de limpieza para evitar errores UAF. El dreamcastcard->timer podría programar el spu_dma_work y el spu_dma_work también podría armar el dreamcastcard->timer. Cuando se cierre snd_pcm_substream, se desasignará aica_channel. Pero aún se podría eliminar la referencia en el hilo del trabajador. La razón es que del_timer() regresará directamente independientemente de si el controlador del temporizador se está ejecutando o no y el trabajador podría reprogramarse en el controlador del temporizador. Como resultado, se producirá el error UAF. La situación picante se muestra a continuación: (Thread 1) | (Thread 2) snd_aicapcm_pcm_close() | ... | run_spu_dma() //worker | mod_timer() flush_work() | del_timer() | aica_period_elapsed() //timer kfree(dreamcastcard->channel) | schedule_work() | run_spu_dma() //worker ... | dreamcastcard->channel-> //USE Para mitigar este error y otros posibles casos extremos, llame a mod_timer() condicionalmente en run_spu_dma(), luego implemente la operación PCM sync_stop para cancelar tanto el temporizador como el trabajador. La operación sync_stop se llamará desde el núcleo PCM de forma adecuada cuando sea necesario.

*Credits: N/A
CVSS Scores
Attack Vector
-
Attack Complexity
-
Privileges Required
-
User Interaction
-
Scope
-
Confidentiality
-
Integrity
-
Availability
-
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-02-19 CVE Reserved
  • 2024-04-01 CVE Published
  • 2024-04-11 EPSS Updated
  • 2024-12-19 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.23 < 4.19.312
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.23 < 4.19.312"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.23 < 5.4.274
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.23 < 5.4.274"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.23 < 5.10.215
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.23 < 5.10.215"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.23 < 5.15.154
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.23 < 5.15.154"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.23 < 6.1.84
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.23 < 6.1.84"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.23 < 6.6.24
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.23 < 6.6.24"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.23 < 6.7.12
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.23 < 6.7.12"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.23 < 6.8.3
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.23 < 6.8.3"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.23 < 6.9
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.23 < 6.9"
en
Affected