CVEvulnerability
CVE-2025-40304
7.8 HIGH
Official page ↗
- Status
- Deferred
- Published
- 2025-12-08
- Last modified
- 2026-10-14
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Description
In the Linux kernel, the following vulnerability has been resolved:
fbdev: Add bounds checking in bit_putcs to fix vmalloc-out-of-bounds
Add bounds checking to prevent writes past framebuffer boundaries when
rendering text near screen edges. Return early if the Y position is off-screen
and clip image height to screen boundary. Break from the rendering loop if the
X position is off-screen. When clipping image width to fit the screen, update
the character count to match the clipped width to prevent buffer size
mismatches.
Without the character count update, bit_putcs_aligned and bit_putcs_unaligned
receive mismatched parameters where the buffer is allocated for the clipped
width but cnt reflects the original larger count, causing out-of-bounds writes.
References
- https://git.kernel.org/stable/c/15ba9acafb0517f8359ca30002c189a68ddbb939 git.kernel.org
- https://git.kernel.org/stable/c/1943b69e87b0ab35032d47de0a7fca9a3d1d6fc1 git.kernel.org
- https://git.kernel.org/stable/c/2d1359e11674ed4274934eac8a71877ae5ae7bbb git.kernel.org
- https://git.kernel.org/stable/c/3637d34b35b287ab830e66048841ace404382b67 git.kernel.org
- https://git.kernel.org/stable/c/86df8ade88d290725554cefd03101ecd0fbd3752 git.kernel.org
- https://git.kernel.org/stable/c/996bfaa7372d6718b6d860bdf78f6618e850c702 git.kernel.org
- https://git.kernel.org/stable/c/ebc0730b490c7f27340b1222e01dd106e820320d git.kernel.org
- https://git.kernel.org/stable/c/f0982400648a3e00580253e0c48e991f34d2684c git.kernel.org