CVE-2025-39967

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux96e41fc29e8af5c5085fb8a79cab8d0d00bab86c < 994bdc2d23c79087fbf7dcd9544454e8ebcef877affected
LinuxLinux39b3cffb8cf3111738ea993e2757ab382253d86a < 9c8ec14075c5317edd6b242f1be8167aa1e4e333affected
LinuxLinux39b3cffb8cf3111738ea993e2757ab382253d86a < b8a6e85328aeb9881531dbe89bcd2637a06c3c95affected
LinuxLinux39b3cffb8cf3111738ea993e2757ab382253d86a < a6eb9f423b3db000aaedf83367b8539f6b72dcfcaffected
LinuxLinux39b3cffb8cf3111738ea993e2757ab382253d86a < adac90bb1aaf45ca66f9db8ac100be16750ace78affected
LinuxLinux39b3cffb8cf3111738ea993e2757ab382253d86a < 4a4bac869560f943edbe3c2b032062f6673b13d3affected
LinuxLinux39b3cffb8cf3111738ea993e2757ab382253d86a < c0c01f9aa08c8e10e10e8c9ebb5be01a4eff6eb7affected
LinuxLinux39b3cffb8cf3111738ea993e2757ab382253d86a < 1a194e6c8e1ee745e914b0b7f50fa86c89ed13feaffected
LinuxLinuxae021a904ac82d9fc81c25329d3c465c5a7d5686affected
LinuxLinux451bffa366f2cc0e5314807cb847f31c0226efedaffected
LinuxLinux2c455e9c5865861f5ce09c5f596909495ed7657caffected
LinuxLinux72f099805dbc907fbe8fa19bccdc31d3e2ee6e9eaffected
LinuxLinux34cf1aff169dc6dedad8d79da7bf1b4de2773dbcaffected
LinuxLinux5.4.62 < 5.4.300affected
LinuxLinux4.4.235 < 4.5affected
LinuxLinux4.9.235 < 4.10affected
LinuxLinux4.14.196 < 4.15affected
LinuxLinux4.19.143 < 4.20affected
LinuxLinux5.8.6 < 5.9affected
LinuxLinux5.9affected
LinuxLinux0 < 5.9unaffected
LinuxLinux5.4.300 <= 5.4.*unaffected
LinuxLinux5.10.245 <= 5.10.*unaffected
LinuxLinux5.15.194 <= 5.15.*unaffected
LinuxLinux6.1.155 <= 6.1.*unaffected
LinuxLinux6.6.109 <= 6.6.*unaffected
LinuxLinux6.12.50 <= 6.12.*unaffected
LinuxLinux6.16.10 <= 6.16.*unaffected
LinuxLinux6.17 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

References