IM
IronMonkey Threat Research

CVE-2025-38685 HIGH

Published: 2025-09-04 | Last Modified: 2026-05-12 | Status: Modified

Description

In the Linux kernel, the following vulnerability has been resolved: fbdev: Fix vmalloc out-of-bounds write in fast_imageblit This issue triggers when a userspace program does an ioctl FBIOPUT_CON2FBMAP by passing console number and frame buffer number. Ideally this maps console to frame buffer and updates the screen if console is visible. As part of mapping it has to do resize of console according to frame buffer info. if this resize fails and returns from vc_do_resize() and continues further. At this point console and new frame buffer are mapped and sets display vars. Despite failure still it continue to proceed updating the screen at later stages where vc_data is related to previous frame buffer and frame buffer info and display vars are mapped to new frame buffer and eventully leading to out-of-bounds write in fast_imageblit(). This bheviour is excepted only when fg_console is equal to requested console which is a visible console and updates screen with invalid struct references in fbcon_putcs().

CVSS Metrics

Base Score: 7.8 (HIGH)

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack VectorLOCAL
Attack ComplexityLOW
Privileges RequiredLOW
User InteractionNONE
ScopeUNCHANGED
Confidentiality ImpactHIGH
Integrity ImpactHIGH
Availability ImpactHIGH

Source: [email protected]

Type: Primary

Exploitability Score: 1.8

Impact Score: 5.9

Weaknesses

Source Type Description
[email protected] Primary
en CWE-787

Affected Products

Vendor Product Version Update Type
linux linux_kernel * <built-in method update of dict object at 0x702bdd12b0c0> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bddc2dac0> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bddc2fe00> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bddc2c640> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bdd2ea840> Operating System
linux linux_kernel * <built-in method update of dict object at 0x702bdd2ebdc0> Operating System
linux linux_kernel 2.6.12 <built-in method update of dict object at 0x702bdd6a4880> Operating System
linux linux_kernel 2.6.12 <built-in method update of dict object at 0x702bdd6a7940> Operating System
linux linux_kernel 2.6.12 <built-in method update of dict object at 0x702bddc2d000> Operating System
linux linux_kernel 2.6.12 <built-in method update of dict object at 0x702bdd2eaac0> Operating System
linux linux_kernel 2.6.12 <built-in method update of dict object at 0x702bddc2c100> Operating System
debian debian_linux 11.0 <built-in method update of dict object at 0x702bddc2cec0> Operating System

Affected Configurations

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:2.6.12:-:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:2.6.12:rc2:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:2.6.12:rc3:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:2.6.12:rc4:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:2.6.12:rc5:*:*:*:*:*:*

Operator: OR

Vulnerable CPE
Yes cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References

Notification
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