CVE-2022-50511

lib/fonts: fix undefined behavior in bit shift for get_default_font

MEDIUM

5.5

CVSS Score

Published: October 7, 2025 at 03:19 PM UTC

Updated: June 17, 2026 at 05:23 AM UTC

1 product affected across 1 vendorLinux Kernel

Using Linux by Linux?

Get instant alerts when new vulnerabilities affect Linux - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

MEDIUM5.5

Exploit prediction

EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: lib/fonts: fix undefined behavior in bit shift for get_default_font Shifting signed 32-bit value by 31 bits is undefined, so changing significant bit to unsigned. The UBSAN warning calltrace like below: UBSAN: shift-out-of-bounds in lib/fonts/fonts.c:139:20 left shift of 1 by 31 places cannot be represented in type 'int' <TASK> dump_stack_lvl+0x7d/0xa5 dump_stack+0x15/0x1b ubsan_epilogue+0xe/0x4e __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c get_default_font+0x1c7/0x1f0 fbcon_startup+0x347/0x3a0 do_take_over_console+0xce/0x270 do_fbcon_takeover+0xa1/0x170 do_fb_registered+0x2a8/0x340 fbcon_fb_registered+0x47/0xe0 register_framebuffer+0x294/0x4a0 __drm_fb_helper_initial_config_and_unlock+0x43c/0x880 [drm_kms_helper] drm_fb_helper_initial_config+0x52/0x80 [drm_kms_helper] drm_fbdev_client_hotplug+0x156/0x1b0 [drm_kms_helper] drm_fbdev_generic_setup+0xfc/0x290 [drm_kms_helper] bochs_pci_probe+0x6ca/0x772 [bochs] local_pci_probe+0x4d/0xb0 pci_device_probe+0x119/0x320 really_probe+0x181/0x550 __driver_probe_device+0xc6/0x220 driver_probe_device+0x32/0x100 __driver_attach+0x195/0x200 bus_for_each_dev+0xbb/0x120 driver_attach+0x27/0x30 bus_add_driver+0x22e/0x2f0 driver_register+0xa9/0x190 __pci_register_driver+0x90/0xa0 bochs_pci_driver_init+0x52/0x1000 [bochs] do_one_initcall+0x76/0x430 do_init_module+0x61/0x28a load_module+0x1f82/0x2e50 __do_sys_finit_module+0xf8/0x190 __x64_sys_finit_module+0x23/0x30 do_syscall_64+0x58/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK>

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

2.6.23 ≤ v < 5.10.1632.6.23 ≤ v < 5.15.862.6.23 ≤ v < 5.4.2292.6.23 ≤ v < 6.0.162.6.23 ≤ v < 6.1.22.6.23 ≤ v < 6.22.6.23.1 ≤ v < 5.4.2295.11 ≤ v < 5.15.865.16 ≤ v < 6.0.165.5 ≤ v < 5.10.1636.1 ≤ v < 6.1.22.6.23 2.6.23 rc2 2.6.23 rc3 2.6.23 rc4 2.6.23 rc5 2.6.23 rc6 2.6.23 rc7 2.6.23 rc8 2.6.23 rc9c81f717cb9e0bd91dc4b98753cb2705ab0fe2801

Vendor states this is fixed in 6fe888c4d2fb174408e4540bb2d5602b9f507f90 (fixed)

Vendor states this is fixed in 890d91b31f4874361e0df047f57d268a7021cb12 (fixed)

Vendor states this is fixed in 9c14a85e18a58c102ec223144b7edb5b345c1bea (fixed)

Vendor states this is fixed in c9a9aa02f0fa3318e0ae5774f404419a1b4759ca (fixed)

Vendor states this is fixed in e039929e36818507e90901edae87f6fa8bc81093 (fixed)

Vendor states this is fixed in e83b47580a0738361772d6f24286adfdaba57e36 (fixed)

Vendor states this is fixed in 2.6.23 (unaffected)

Vendor states this is fixed in 5.10.163 (unaffected)

Vendor states this is fixed in 5.15.86 (unaffected)

Vendor states this is fixed in 5.4.229 (unaffected)

Vendor states this is fixed in 6.0.16 (unaffected)

Vendor states this is fixed in 6.1.2 (unaffected)