CVE-2024-26654 ALSA: sh: aica: reorder cleanup operations to avoid UAF bugs

2024-04-0108:35:19

Linux

www.cve.org

linux kernel

vulnerability

alsa

aica

uaf

bug fix

pcm

sync_stop

timer

worker

7 High

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

13.2%

JSON

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)

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.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "sound/sh/aica.c"
    ],
    "versions": [
      {
        "version": "198de43d758c",
        "lessThan": "eeb2a2ca0b8d",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "198de43d758c",
        "lessThan": "4206ad65a0ee",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "198de43d758c",
        "lessThan": "aa39e6878f61",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "198de43d758c",
        "lessThan": "8c9902216816",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "198de43d758c",
        "lessThan": "9d66ae0e7bb7",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "198de43d758c",
        "lessThan": "61d4787692c1",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "198de43d758c",
        "lessThan": "e955e8a7f38a",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "198de43d758c",
        "lessThan": "3c907bf56905",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "198de43d758c",
        "lessThan": "051e0840ffa8",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "sound/sh/aica.c"
    ],
    "versions": [
      {
        "version": "2.6.23",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "2.6.23",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.312",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.274",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.215",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.154",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.84",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.24",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.7.12",
        "lessThanOrEqual": "6.7.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8.3",
        "lessThanOrEqual": "6.8.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]