CVE-2021-47641

Estado: ModificadaMedia (5.5)—

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

video: fbdev: cirrusfb: check pixclock to avoid divide by zero

Do a sanity check on pixclock value to avoid divide by zero.

If the pixclock value is zero, the cirrusfb driver will round up pixclock to get the derived frequency as close to maxclock as possible.

Syzkaller reported a divide error in cirrusfb_check_pixclock.

Detalles técnicos trazas, registros y código del informe original

divide error: 0000 [#1] SMP KASAN PTI
CPU: 0 PID: 14938 Comm: cirrusfb_test Not tainted 5.15.0-rc6 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2
RIP: 0010:cirrusfb_check_var+0x6f1/0x1260

Call Trace:
 fb_set_var+0x398/0xf90
 do_fb_ioctl+0x4b8/0x6f0
 fb_ioctl+0xeb/0x130
 __x64_sys_ioctl+0x19d/0x220
 do_syscall_64+0x3a/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Puntuación base: 5.5

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.26%
Percentil entre todas las CVEs puntuadas: 16
Fecha de la puntuación: 6/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-369
CWE-369

Referencias

JSON original (NVD)

Mostrar

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      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvideo: fbdev: cirrusfb: check pixclock to avoid divide by zero\n\nDo a sanity check on pixclock value to avoid divide by zero.\n\nIf the pixclock value is zero, the cirrusfb driver will round up\npixclock to get the derived frequency as close to maxclock as\npossible.\n\nSyzkaller reported a divide error in cirrusfb_check_pixclock.\n\ndivide error: 0000 [#1] SMP KASAN PTI\nCPU: 0 PID: 14938 Comm: cirrusfb_test Not tainted 5.15.0-rc6 #1\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2\nRIP: 0010:cirrusfb_check_var+0x6f1/0x1260\n\nCall Trace:\n fb_set_var+0x398/0xf90\n do_fb_ioctl+0x4b8/0x6f0\n fb_ioctl+0xeb/0x130\n __x64_sys_ioctl+0x19d/0x220\n do_syscall_64+0x3a/0x80\n entry_SYSCALL_64_after_hwframe+0x44/0xae"
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      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: video: fbdev: cirrusfb: comprobar pixclock para evitar la división por cero Realice una comprobación de la depuración del valor de pixclock para evitar la división por cero. Si el valor de pixclock es cero, el controlador cirrusfb redondeará el valor de pixclock para obtener la frecuencia derivada lo más cercana posible a maxclock. Syzkaller informó un error de división en cirrusfb_check_pixclock. Error de división: 0000 [#1] SMP KASAN PTI CPU: 0 PID: 14938 Comm: cirrusfb_test No contaminado 5.15.0-rc6 #1 Nombre del hardware: PC estándar QEMU (i440FX + PIIX, 1996), BIOS 1.11.0-2 RIP: 0010:cirrusfb_check_var+0x6f1/0x1260 Seguimiento de llamadas: fb_set_var+0x398/0xf90 do_fb_ioctl+0x4b8/0x6f0 fb_ioctl+0xeb/0x130 __x64_sys_ioctl+0x19d/0x220 do_syscall_64+0x3a/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae"
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