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().
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().
Metrics
Affected Vendors & Products
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 05 Sep 2025 14:15:00 +0000
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Linux
Linux linux Kernel |
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Vendors & Products |
Linux
Linux linux Kernel |
Fri, 05 Sep 2025 00:15:00 +0000
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References |
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Metrics |
threat_severity
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cvssV3_1
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Thu, 04 Sep 2025 15:45:00 +0000
Type | Values Removed | Values Added |
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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(). | |
Title | fbdev: Fix vmalloc out-of-bounds write in fast_imageblit | |
References |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-09-04T15:32:39.856Z
Reserved: 2025-04-16T04:51:24.032Z
Link: CVE-2025-38685

No data.

Status : Awaiting Analysis
Published: 2025-09-04T16:15:36.397
Modified: 2025-09-05T17:47:24.833
Link: CVE-2025-38685


Updated: 2025-09-05T14:02:49Z