CVE-2025-21976

In the Linux kernel, the following vulnerability has been resolved: fbdev: hyperv_fb: Allow graceful removal of framebuffer When a Hyper-V framebuffer device is unbind, hyperv_fb driver tries to release the framebuffer forcefully. If this framebuffer is in use it produce the following WARN and hence this framebuffer is never released. [ 44.111220] WARNING: CPU: 35 PID: 1882 at drivers/video/fbdev/core/fb_info.c:70 framebuffer_release+0x2c/0x40 < snip > [ 44.111289] Call Trace: [ 44.111290] <TASK> [ 44.111291] ? show_regs+0x6c/0x80 [ 44.111295] ? __warn+0x8d/0x150 [ 44.111298] ? framebuffer_release+0x2c/0x40 [ 44.111300] ? report_bug+0x182/0x1b0 [ 44.111303] ? handle_bug+0x6e/0xb0 [ 44.111306] ? exc_invalid_op+0x18/0x80 [ 44.111308] ? asm_exc_invalid_op+0x1b/0x20 [ 44.111311] ? framebuffer_release+0x2c/0x40 [ 44.111313] ? hvfb_remove+0x86/0xa0 [hyperv_fb] [ 44.111315] vmbus_remove+0x24/0x40 [hv_vmbus] [ 44.111323] device_remove+0x40/0x80 [ 44.111325] device_release_driver_internal+0x20b/0x270 [ 44.111327] ? bus_find_device+0xb3/0xf0 Fix this by moving the release of framebuffer and assosiated memory to fb_ops.fb_destroy function, so that framebuffer framework handles it gracefully. While we fix this, also replace manual registrations/unregistration of framebuffer with devm_register_framebuffer.
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:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:*

History

30 Oct 2025, 21:00

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.5
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: fbdev: hyperv_fb: Permite la eliminación ordenada del framebuffer. Cuando se desvincula un dispositivo framebuffer de Hyper-V, el controlador hyperv_fb intenta liberarlo forzosamente. Si este framebuffer está en uso, genera la siguiente advertencia y, por lo tanto, nunca se libera. [44.111220] ADVERTENCIA: CPU: 35 PID: 1882 en drivers/video/fbdev/core/fb_info.c:70 framebuffer_release+0x2c/0x40 &lt; snip &gt; [44.111289] Rastreo de llamadas: [ 44.111290] [ 44.111291] ? show_regs+0x6c/0x80 [ 44.111295] ? __warn+0x8d/0x150 [ 44.111298] ? framebuffer_release+0x2c/0x40 [ 44.111300] ? report_bug+0x182/0x1b0 [ 44.111303] ? handle_bug+0x6e/0xb0 [ 44.111306] ? exc_invalid_op+0x18/0x80 [ 44.111308] ? asm_exc_invalid_op+0x1b/0x20 [ 44.111311] ? framebuffer_release+0x2c/0x40 [ 44.111313] ? hvfb_remove+0x86/0xa0 [hyperv_fb] [ 44.111315] vmbus_remove+0x24/0x40 [hv_vmbus] [ 44.111323] device_remove+0x40/0x80 [ 44.111325] device_release_driver_internal+0x20b/0x270 [ 44.111327] ? bus_find_device+0xb3/0xf0. Solucione esto trasladando la liberación del framebuffer y la memoria asociada a la función fb_ops.fb_destroy, para que el framework del framebuffer lo gestione correctamente. Mientras lo solucionamos, también reemplace el registro/desregistro manual del framebuffer con devm_register_framebuffer.
References () https://git.kernel.org/stable/c/4545e2aa121aea304d33903099c03e29ed4fe50a - () https://git.kernel.org/stable/c/4545e2aa121aea304d33903099c03e29ed4fe50a - Patch
References () https://git.kernel.org/stable/c/a7b583dc99c6cf4a96877017be1d08247e1ef2c7 - () https://git.kernel.org/stable/c/a7b583dc99c6cf4a96877017be1d08247e1ef2c7 - Patch
References () https://git.kernel.org/stable/c/ea2f45ab0e53b255f72c85ccd99e2b394fc5fceb - () https://git.kernel.org/stable/c/ea2f45ab0e53b255f72c85ccd99e2b394fc5fceb - Patch
CPE cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:*
First Time Linux linux Kernel
Linux
CWE NVD-CWE-noinfo

01 Apr 2025, 16:15

Type Values Removed Values Added
New CVE

Information

Published : 2025-04-01 16:15

Updated : 2025-10-30 21:00


NVD link : CVE-2025-21976

Mitre link : CVE-2025-21976

CVE.ORG link : CVE-2025-21976


JSON object : View

Products Affected

linux

  • linux_kernel