CVE-2025-39967
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.
How to fix
- linux linux_kernel4.5, 4.10, 4.15, 4.20, 5.4.300, 5.9, 5.10.245, 5.15.194, 6.1.155, 6.6.109, 6.12.50, 6.16.10 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 4.4.235 ≤ v < 4.5, 4.9.235 ≤ v < 4.10, 4.14.196 ≤ v < 4.15, 4.19.143 ≤ v < 4.20, 5.4.62 ≤ v < 5.4.300, 5.8.6 ≤ v < 5.9, 5.9.1 ≤ v < 5.10.245, 5.11 ≤ v < 5.15.194, 5.16 ≤ v < 6.1.155, 6.2 ≤ v < 6.6.109, 6.7 ≤ v < 6.12.50, 6.13 ≤ v < 6.16.10, 5.9, 6.17 | 4.5, 4.10, 4.15, 4.20, 5.4.300, 5.9, 5.10.245, 5.15.194, 6.1.155, 6.6.109, 6.12.50, 6.16.10 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.