CVE-2025-39967
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.16%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.16% probability · 5th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-190
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.