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>
Metrics
Affected Vendors & Products
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References
History
Tue, 07 Oct 2025 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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> | |
| Title | lib/fonts: fix undefined behavior in bit shift for get_default_font | |
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-10-07T15:19:08.159Z
Reserved: 2025-10-07T15:11:44.887Z
Link: CVE-2022-50511
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-10-07T16:15:34.337
Modified: 2025-10-07T16:15:34.337
Link: CVE-2022-50511
Redhat
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OpenCVE Enrichment
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