linux/arch/x86/boot
Ashish Kalra d594aa0277 x86/boot: Fix BSS corruption/overwrite bug in early x86 kernel startup
The minimum size for a new stack (512 bytes) setup for arch/x86/boot components
when the bootloader does not setup/provide a stack for the early boot components
is not "enough".

The setup code executing as part of early kernel startup code, uses the stack
beyond 512 bytes and accidentally overwrites and corrupts part of the BSS
section. This is exposed mostly in the early video setup code, where
it was corrupting BSS variables like force_x, force_y, which in-turn affected
kernel parameters such as screen_info (screen_info.orig_video_cols) and
later caused an exception/panic in console_init().

Most recent boot loaders setup the stack for early boot components, so this
stack overwriting into BSS section issue has not been exposed.

Signed-off-by: Ashish Kalra <ashish@bluestacks.com>
Cc: <stable@vger.kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170419152015.10011-1-ashishkalra@Ashishs-MacBook-Pro.local
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-20 10:05:23 +02:00
..
compressed Merge branch 'WIP.x86/boot' into x86/boot, to pick up ready branch 2017-04-11 08:49:31 +02:00
tools x86/boot: Remove unused 'is_big_kernel' variable 2016-02-16 09:16:58 +01:00
.gitignore x86: remove offsets.h from .gitignore and dontdiff 2012-11-19 14:10:53 +01:00
a20.c x86, setup: "glove box" BIOS interrupts in the core boot code 2009-04-09 16:08:11 -07:00
apm.c x86, setup: "glove box" BIOS interrupts in the APM code 2009-04-09 16:08:11 -07:00
bioscall.S x86, boot: Move intcall() to the .inittext section 2014-01-04 14:29:08 -08:00
bitops.h x86, asm: use bool for bitops and other assembly outputs 2016-06-08 12:41:20 -07:00
boot.h x86/boot: Fix BSS corruption/overwrite bug in early x86 kernel startup 2017-04-20 10:05:23 +02:00
cmdline.c x86, boot: Pass cmd_line_ptr with unsigned long instead 2013-01-29 15:26:09 -08:00
code16gcc.h x86, build: Change code16gcc.h from a C header to an assembly header 2014-06-04 13:16:48 -07:00
copy.S x86, boot: Use .code16 instead of .code16gcc 2014-01-04 13:59:06 -08:00
cpu.c Revert "x86/boot: Fail the boot if !M486 and CPUID is missing" 2016-12-19 11:54:20 +01:00
cpucheck.c x86/mm: Disallow running with 32-bit PTEs to work around erratum 2016-07-13 09:43:25 +02:00
cpuflags.c x86/mm: Disallow running with 32-bit PTEs to work around erratum 2016-07-13 09:43:25 +02:00
cpuflags.h x86/mm: Disallow running with 32-bit PTEs to work around erratum 2016-07-13 09:43:25 +02:00
ctype.h x86, setup: Rename BOOT_ISDIGIT_H to BOOT_CTYPE_H 2015-01-13 11:59:04 +01:00
early_serial_console.c x86/boot: Add missing file header comments 2016-05-10 10:12:03 +02:00
edd.c x86, boot: Create a separate string.h file to provide standard string functions 2014-03-19 15:43:45 -07:00
header.S x86/boot/e820: Remove assembly guard from asm/e820/types.h 2017-01-28 09:31:15 +01:00
install.sh kbuild: use INSTALLKERNEL to select customized installkernel script 2009-09-20 12:18:14 +02:00
main.c x86/boot: Obsolete the MCA sys_desc_table 2015-07-21 10:55:11 +02:00
Makefile x86/boot/build: Remove always empty $(USERINCLUDE) 2016-11-07 07:30:01 +01:00
memory.c x86/boot/e820: Separate the E820 ABI structures from the in-kernel structures 2017-01-29 13:39:32 +01:00
mkcpustr.c x86/cpufeature: Carve out X86_FEATURE_* 2016-01-30 11:22:17 +01:00
mtools.conf.in
pm.c x86: remove zImage support 2009-03-11 11:00:00 -07:00
pmjump.S x86, setup: move 32-bit code to .text32 2009-03-17 15:26:06 -07:00
printf.c x86/boot: Fix a sanity check in printf.c 2013-08-14 11:48:41 +02:00
regs.c x86, boot: Create a separate string.h file to provide standard string functions 2014-03-19 15:43:45 -07:00
setup.ld x86, boot: Define the 2.12 bzImage boot protocol 2013-01-27 15:56:37 -08:00
string.c Merge branch 'linus' into x86/boot, to pick up fixes 2017-01-28 09:30:11 +01:00
string.h x86/boot: Add missing declaration of string functions 2017-01-09 11:53:05 +01:00
tty.c x86, setup: reorganize the early console setup 2010-08-02 15:51:56 -07:00
version.c kbuild: move utsrelease.h to include/generated 2009-12-12 13:08:15 +01:00
vesa.h
video-bios.c x86: fix usage of bios intcall() 2009-07-04 12:56:32 -07:00
video-mode.c x86/mm: Fix regression with huge pages on PAE 2015-12-04 09:14:27 +01:00
video-vesa.c x86, boot: Create a separate string.h file to provide standard string functions 2014-03-19 15:43:45 -07:00
video-vga.c x86, setup: Set ax register in boot vga query 2010-06-10 15:24:29 -07:00
video.c x86/mm: Fix regression with huge pages on PAE 2015-12-04 09:14:27 +01:00
video.h x86/boot/video: Move the 'video_segment' variable to video.c 2015-02-19 00:25:05 +01:00