CVE-2022-49978

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2022-49978
In the Linux kernel, the following vulnerability has been resolved: fbdev: fb_pm2fb: Avoid potential divide by zero error In `do_fb_ioctl()` of fbmem.c, if cmd is FBIOPUT_VSCREENINFO, var will be copied from user, then go through `fb_set_var()` and `info->fbops->fb_check_var()` which could may be `pm2fb_check_var()`. Along the path, `var->pixclock` won't be modified. This function checks whether reciprocal of `var->pixclock` is too high. If `var->pixclock` is zero, there will be a divide by zero error. So, it is necessary to check whether denominator is zero to avoid crash. As this bug is found by Syzkaller, logs are listed below. divide error in pm2fb_check_var Call Trace: <TASK> fb_set_var+0x367/0xeb0 drivers/video/fbdev/core/fbmem.c:1015 do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/0f1174f4972ea9fad6becf8881d71adca8e9ca91 Patch
https://git.kernel.org/stable/c/19f953e7435644b81332dd632ba1b2d80b1e37af Patch
https://git.kernel.org/stable/c/34c3dea1189525cd533071ed5c176fc4ea8d982b Patch
https://git.kernel.org/stable/c/3ec326a6a0d4667585ca595f438c7293e5ced7c4 Patch
https://git.kernel.org/stable/c/7d9591b32a9092fc6391a316b56e8016c6181c3d Patch
https://git.kernel.org/stable/c/7f88cdfea8d7f4dbaf423d808241403b2bb945e4 Patch
https://git.kernel.org/stable/c/8fc778ee2fb2853f7a3531fa7273349640d8e4e9 Patch
https://git.kernel.org/stable/c/cb4bb011a683532841344ca7f281b5e04389b4f8 Patch
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:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:*
History

14 Nov 2025, 18:16

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: fbdev: fb_pm2fb: Evitar posible error de división por cero En `do_fb_ioctl()` de fbmem.c, si cmd es FBIOPUT_VSCREENINFO, var se copiará del usuario, luego pasará por `fb_set_var()` e `info-&gt;fbops-&gt;fb_check_var()` que podrían ser `pm2fb_check_var()`. A lo largo de la ruta, `var-&gt;pixclock` no se modificará. Esta función verifica si el recíproco de `var-&gt;pixclock` es demasiado alto. Si `var-&gt;pixclock` es cero, habrá un error de división por cero. Por lo tanto, es necesario verificar si el denominador es cero para evitar un bloqueo. Como Syzkaller encontró este error, los registros se enumeran a continuación. Error de división en el seguimiento de llamadas pm2fb_check_var: fb_set_var+0x367/0xeb0 drivers/video/fbdev/core/fbmem.c:1015 do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:*
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5
CWE CWE-369
References () https://git.kernel.org/stable/c/0f1174f4972ea9fad6becf8881d71adca8e9ca91 - () https://git.kernel.org/stable/c/0f1174f4972ea9fad6becf8881d71adca8e9ca91 - Patch
References () https://git.kernel.org/stable/c/19f953e7435644b81332dd632ba1b2d80b1e37af - () https://git.kernel.org/stable/c/19f953e7435644b81332dd632ba1b2d80b1e37af - Patch
References () https://git.kernel.org/stable/c/34c3dea1189525cd533071ed5c176fc4ea8d982b - () https://git.kernel.org/stable/c/34c3dea1189525cd533071ed5c176fc4ea8d982b - Patch
References () https://git.kernel.org/stable/c/3ec326a6a0d4667585ca595f438c7293e5ced7c4 - () https://git.kernel.org/stable/c/3ec326a6a0d4667585ca595f438c7293e5ced7c4 - Patch
References () https://git.kernel.org/stable/c/7d9591b32a9092fc6391a316b56e8016c6181c3d - () https://git.kernel.org/stable/c/7d9591b32a9092fc6391a316b56e8016c6181c3d - Patch
References () https://git.kernel.org/stable/c/7f88cdfea8d7f4dbaf423d808241403b2bb945e4 - () https://git.kernel.org/stable/c/7f88cdfea8d7f4dbaf423d808241403b2bb945e4 - Patch
References () https://git.kernel.org/stable/c/8fc778ee2fb2853f7a3531fa7273349640d8e4e9 - () https://git.kernel.org/stable/c/8fc778ee2fb2853f7a3531fa7273349640d8e4e9 - Patch
References () https://git.kernel.org/stable/c/cb4bb011a683532841344ca7f281b5e04389b4f8 - () https://git.kernel.org/stable/c/cb4bb011a683532841344ca7f281b5e04389b4f8 - Patch
First Time Linux
Linux linux Kernel

18 Jun 2025, 11:15

Type Values Removed Values Added
New CVE
Information

Published : 2025-06-18 11:15

Updated : 2025-11-14 18:16

NVD link : CVE-2022-49978

Mitre link : CVE-2022-49978

CVE.ORG link : CVE-2022-49978

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-369

Divide By Zero