CVE-2025-40322
Published: December 9, 2025Last modified: June 24, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: fbdev: bitblit: bound-check glyph index in bit_putcs* bit_putcs_aligned()/unaligned() derived the glyph pointer from the character value masked by 0xff/0x1ff, which may exceed the actual font's glyph count and read past the end of the built-in font array. Clamp the index to the actual glyph count before computing the address. This fixes a global out-of-bounds read reported by syzbot.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.1 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.159-r0) |
| 25 LTS | linux-lts | Fixed (6.12.58-r0) | |
| Stream | linux-lts | Fixed (6.18.35-r1) |
References
- https://git.kernel.org/stable/c/0998a6cb232674408a03e8561dc15aa266b2f53b
- https://git.kernel.org/stable/c/18c4ef4e765a798b47980555ed665d78b71aeadf
- https://git.kernel.org/stable/c/901f44227072be60812fe8083e83e1533c04eed1
- https://git.kernel.org/stable/c/9ba1a7802ca9a2590cef95b253e6526f4364477f
- https://git.kernel.org/stable/c/a10cede006f9614b465cf25609a8753efbfd45cc
- https://git.kernel.org/stable/c/c12003bf91fdff381c55ef54fef3e961a5af2545
- https://git.kernel.org/stable/c/db5c9a162d2f42bcc842b76b3d935dcc050a0eec
- https://git.kernel.org/stable/c/efaf89a75a29b2d179bf4fe63ca62852e93ad620