Description
In the Linux kernel, the following vulnerability has been resolved:
fbcon: fix integer overflow in fbcon_do_set_font
Fix integer overflow vulnerabilities in fbcon_do_set_font() where font size calculations could overflow when handling user-controlled font parameters.
The vulnerabilities occur when: 1. CALC_FONTSZ(h, pitch, charcount) performs h * pith * charcount multiplication with user-controlled values that can overflow. 2. FONT_EXTRA_WORDS * sizeof(int) + size addition can also overflow 3. This results in smaller allocations than expected, leading to buffer overflows during font data copying.
Add explicit overflow checking using check_mul_overflow() and check_add_overflow() kernel helpers to safety validate all size calculations before allocation.
Metrics
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= 96e41fc29e8af5c5085fb8a79cab8d0d00bab86c, < 994bdc2d23c79087fbf7dcd9544454e8ebcef877; >= 39b3cffb8cf3111738ea993e2757ab382253d86a, < 9c8ec14075c5317edd6b242f1be8167aa1e4e333; >= 39b3cffb8cf3111738ea993e2757ab382253d86a, < b8a6e85328aeb9881531dbe89bcd2637a06c3c95; >= 39b3cffb8cf3111738ea993e2757ab382253d86a, < a6eb9f423b3db000aaedf83367b8539f6b72dcfc; >= 39b3cffb8cf3111738ea993e2757ab382253d86a, < adac90bb1aaf45ca66f9db8ac100be16750ace78; >= 39b3cffb8cf3111738ea993e2757ab382253d86a, < 4a4bac869560f943edbe3c2b032062f6673b13d3; >= 39b3cffb8cf3111738ea993e2757ab382253d86a, < c0c01f9aa08c8e10e10e8c9ebb5be01a4eff6eb7; >= 39b3cffb8cf3111738ea993e2757ab382253d86a, < 1a194e6c8e1ee745e914b0b7f50fa86c89ed13fe; ae021a904ac82d9fc81c25329d3c465c5a7d5686; 451bffa366f2cc0e5314807cb847f31c0226efed; 2c455e9c5865861f5ce09c5f596909495ed7657c; 72f099805dbc907fbe8fa19bccdc31d3e2ee6e9e; 34cf1aff169dc6dedad8d79da7bf1b4de2773dbc; >= 5.4.62, < 5.4.300; >= 4.4.235, < 4.5; >= 4.9.235, < 4.10; >= 4.14.196, < 4.15; >= 4.19.143, < 4.20; >= 5.8.6, < 5.9 |
| Linux | Linux | 5.9 |
References
- https://git.kernel.org/stable/c/1a194e6c8e1ee745e914b0b7f50fa86c89ed13fePatch
- https://git.kernel.org/stable/c/4a4bac869560f943edbe3c2b032062f6673b13d3Patch
- https://git.kernel.org/stable/c/994bdc2d23c79087fbf7dcd9544454e8ebcef877Patch
- https://git.kernel.org/stable/c/9c8ec14075c5317edd6b242f1be8167aa1e4e333Patch
- https://git.kernel.org/stable/c/a6eb9f423b3db000aaedf83367b8539f6b72dcfcPatch
- https://git.kernel.org/stable/c/adac90bb1aaf45ca66f9db8ac100be16750ace78Patch
- https://git.kernel.org/stable/c/b8a6e85328aeb9881531dbe89bcd2637a06c3c95Patch
- https://git.kernel.org/stable/c/c0c01f9aa08c8e10e10e8c9ebb5be01a4eff6eb7Patch
Timeline
- Published
- Oct 15, 2025
- Last modified
- Oct 19, 2026
- NVD status
- Modified