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Vulnerability · Published Oct 7, 2025 · Assigned by Linux

CVE-2022-50511lib/fonts: fix undefined behavior in bit shift for get_default_font

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.2%top 94.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.4-1DEBIAN-CVE-2022-50511
Debian:13linux6.1.4-1DEBIAN-CVE-2022-50511
Debian:14linux6.1.4-1DEBIAN-CVE-2022-50511
Ubuntu:22.04:LTSlinux5.15.0-69.76UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-aws5.15.0-1033.37UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-azure5.15.0-1035.42UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2022-50511
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1035.42.1UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-gcp5.15.0-1031.38UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2022-50511
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-gke5.15.0-1030.35UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1017.22UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2022-50511
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-ibm5.15.0-1027.30UBUNTU-CVE-2022-50511
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1027.32UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-kvm5.15.0-1030.35UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-69.76UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2022-50511
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1023.23UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2022-50511
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2022-50511
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-oracle5.15.0-1032.38UBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-raspi5.15.0-1026.28UBUNTU-CVE-2022-50511
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2022-50511
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2022-50511
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2022-50511
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2022-50511

Affected products (as reported)

VendorProductVersions
Linux Linux c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 – before e039929e36818507e90901edae87f6fa8bc81093c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 – before c9a9aa02f0fa3318e0ae5774f404419a1b4759cac81f717cb9e0bd91dc4b98753cb2705ab0fe2801 – before e83b47580a0738361772d6f24286adfdaba57e36c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 – before 9c14a85e18a58c102ec223144b7edb5b345c1beac81f717cb9e0bd91dc4b98753cb2705ab0fe2801 – before 890d91b31f4874361e0df047f57d268a7021cb12c81f717cb9e0bd91dc4b98753cb2705ab0fe2801 – before 6fe888c4d2fb174408e4540bb2d5602b9f507f90
Linux Linux 2.6.23

References