linux-stable/lib/fonts
Gaosheng Cui 6fe888c4d2 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>

Link: https://lkml.kernel.org/r/20221031113829.4183153-1-cuigaosheng1@huawei.com
Fixes: c81f717cb9 ("fbcon: Fix typo and bogus logic in get_default_font")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-18 13:55:09 -08:00
..
font_6x8.c Fonts: Add charcount field to font_desc 2020-11-16 16:31:41 +01:00
font_6x10.c Fonts: Add charcount field to font_desc 2020-11-16 16:31:41 +01:00
font_6x11.c Fonts: Add charcount field to font_desc 2020-11-16 16:31:41 +01:00
font_7x14.c Fonts: Add charcount field to font_desc 2020-11-16 16:31:41 +01:00
font_8x8.c Fonts: Add charcount field to font_desc 2020-11-16 16:31:41 +01:00
font_8x16.c Fonts: Add charcount field to font_desc 2020-11-16 16:31:41 +01:00
font_10x18.c Fonts: Add charcount field to font_desc 2020-11-16 16:31:41 +01:00
font_acorn_8x8.c Fonts: Add charcount field to font_desc 2020-11-16 16:31:41 +01:00
font_mini_4x6.c Fonts: Add charcount field to font_desc 2020-11-16 16:31:41 +01:00
font_pearl_8x8.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
font_sun8x16.c Fonts: Add charcount field to font_desc 2020-11-16 16:31:41 +01:00
font_sun12x22.c Fonts: Add charcount field to font_desc 2020-11-16 16:31:41 +01:00
font_ter16x32.c Fonts: font_ter16x32: Update font with new upstream Terminus release 2021-01-07 21:06:25 +01:00
fonts.c lib/fonts: fix undefined behavior in bit shift for get_default_font 2022-11-18 13:55:09 -08:00
Kconfig lib/fonts: add font 6x8 for OLED display 2020-09-08 13:33:21 +02:00
Makefile lib/fonts: add font 6x8 for OLED display 2020-09-08 13:33:21 +02:00