CVE-2023-52486

In the Linux kernel, the following vulnerability has been resolved: drm: Don't unref the same fb many times by mistake due to deadlock handling If we get a deadlock after the fb lookup in drm_mode_page_flip_ioctl() we proceed to unref the fb and then retry the whole thing from the top. But we forget to reset the fb pointer back to NULL, and so if we then get another error during the retry, before the fb lookup, we proceed the unref the same fb again without having gotten another reference. The end result is that the fb will (eventually) end up being freed while it's still in use. Reset fb to NULL once we've unreffed it to avoid doing it again until we've done another fb lookup. This turned out to be pretty easy to hit on a DG2 when doing async flips (and CONFIG_DEBUG_WW_MUTEX_SLOWPATH=y). The first symptom I saw that drm_closefb() simply got stuck in a busy loop while walking the framebuffer list. Fortunately I was able to convince it to oops instead, and from there it was easier to track down the culprit.
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

History

14 Jan 2025, 15:01

Type Values Removed Values Added
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
References () https://git.kernel.org/stable/c/376e21a9e4c2c63ee5d8d3aa74be5082c3882229 - () https://git.kernel.org/stable/c/376e21a9e4c2c63ee5d8d3aa74be5082c3882229 - Patch
References () https://git.kernel.org/stable/c/62f2e79cf9f4f47cc9dea9cebdf58d9f7b5695e0 - () https://git.kernel.org/stable/c/62f2e79cf9f4f47cc9dea9cebdf58d9f7b5695e0 - Patch
References () https://git.kernel.org/stable/c/9dd334a8245011ace45e53298175c7b659edb3e7 - () https://git.kernel.org/stable/c/9dd334a8245011ace45e53298175c7b659edb3e7 - Patch
References () https://git.kernel.org/stable/c/b4af63da9d94986c529d74499fdfe44289acd551 - () https://git.kernel.org/stable/c/b4af63da9d94986c529d74499fdfe44289acd551 - Patch
References () https://git.kernel.org/stable/c/bfd0feb1b109cb63b87fdcd00122603787c75a1a - () https://git.kernel.org/stable/c/bfd0feb1b109cb63b87fdcd00122603787c75a1a - Patch
References () https://git.kernel.org/stable/c/cb4daf271302d71a6b9a7c01bd0b6d76febd8f0c - () https://git.kernel.org/stable/c/cb4daf271302d71a6b9a7c01bd0b6d76febd8f0c - Patch
References () https://git.kernel.org/stable/c/d7afdf360f4ac142832b098b4de974e867cc063c - () https://git.kernel.org/stable/c/d7afdf360f4ac142832b098b4de974e867cc063c - Patch
References () https://git.kernel.org/stable/c/f55261469be87c55df13db76dc945f6bcd825105 - () https://git.kernel.org/stable/c/f55261469be87c55df13db76dc945f6bcd825105 - Patch
References () https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html - () https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html - Mailing List
References () https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html - () https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html - Mailing List
CWE CWE-667
First Time Linux
Linux linux Kernel
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.5

21 Nov 2024, 08:39

Type Values Removed Values Added
References
  • () https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html -
  • () https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html -
References () https://git.kernel.org/stable/c/376e21a9e4c2c63ee5d8d3aa74be5082c3882229 - () https://git.kernel.org/stable/c/376e21a9e4c2c63ee5d8d3aa74be5082c3882229 -
References () https://git.kernel.org/stable/c/62f2e79cf9f4f47cc9dea9cebdf58d9f7b5695e0 - () https://git.kernel.org/stable/c/62f2e79cf9f4f47cc9dea9cebdf58d9f7b5695e0 -
References () https://git.kernel.org/stable/c/9dd334a8245011ace45e53298175c7b659edb3e7 - () https://git.kernel.org/stable/c/9dd334a8245011ace45e53298175c7b659edb3e7 -
References () https://git.kernel.org/stable/c/b4af63da9d94986c529d74499fdfe44289acd551 - () https://git.kernel.org/stable/c/b4af63da9d94986c529d74499fdfe44289acd551 -
References () https://git.kernel.org/stable/c/bfd0feb1b109cb63b87fdcd00122603787c75a1a - () https://git.kernel.org/stable/c/bfd0feb1b109cb63b87fdcd00122603787c75a1a -
References () https://git.kernel.org/stable/c/cb4daf271302d71a6b9a7c01bd0b6d76febd8f0c - () https://git.kernel.org/stable/c/cb4daf271302d71a6b9a7c01bd0b6d76febd8f0c -
References () https://git.kernel.org/stable/c/d7afdf360f4ac142832b098b4de974e867cc063c - () https://git.kernel.org/stable/c/d7afdf360f4ac142832b098b4de974e867cc063c -
References () https://git.kernel.org/stable/c/f55261469be87c55df13db76dc945f6bcd825105 - () https://git.kernel.org/stable/c/f55261469be87c55df13db76dc945f6bcd825105 -

04 Nov 2024, 13:16

Type Values Removed Values Added
References
  • {'url': 'https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html', 'source': '416baaa9-dc9f-4396-8d5f-8c081fb06d67'}
  • {'url': 'https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html', 'source': '416baaa9-dc9f-4396-8d5f-8c081fb06d67'}

27 Jun 2024, 13:15

Type Values Removed Values Added
References
  • () https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html -

25 Jun 2024, 23:15

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: drm: No desreferenciar el mismo fb muchas veces por error debido al manejo de interbloqueos Si obtenemos un punto muerto después de la búsqueda de fb en drm_mode_page_flip_ioctl() procedemos a desreferenciar el fb y luego Vuelva a intentarlo todo desde arriba. Pero nos olvidamos de restablecer el puntero fb a NULL, por lo que si obtenemos otro error durante el reintento, antes de la búsqueda de fb, procedemos a desref el mismo fb nuevamente sin haber obtenido otra referencia. El resultado final es que el Facebook (eventualmente) terminará siendo liberado mientras todavía está en uso. Restablezca fb a NULL una vez que lo hayamos eliminado para evitar hacerlo nuevamente hasta que hayamos realizado otra búsqueda de fb. Esto resultó ser bastante fácil de lograr en un DG2 cuando se realizan volteos asíncronos (y CONFIG_DEBUG_WW_MUTEX_SLOWPATH=y). El primer síntoma que vi fue que drm_closefb() simplemente se quedó atascado en un bucle ocupado mientras recorría la lista de framebuffer. Afortunadamente, pude convencerlo de que lo hiciera, y a partir de ahí fue más fácil localizar al culpable.
References
  • () https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html -

11 Mar 2024, 18:15

Type Values Removed Values Added
New CVE

Information

Published : 2024-03-11 18:15

Updated : 2025-01-14 15:01


NVD link : CVE-2023-52486

Mitre link : CVE-2023-52486

CVE.ORG link : CVE-2023-52486


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-667

Improper Locking