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| author | Ard Biesheuvel <ardb@kernel.org> | 2025-03-06 16:59:16 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-03-13 13:07:44 +0100 |
| commit | c1f4dea5bf9014e4733a738cfdaa8562e579715c (patch) | |
| tree | 7eddd0cf805d4249a54de40162643b8b99f0d717 /arch/x86 | |
| parent | bac199381cd74adfbdecc4efeec4ad007fb759c8 (diff) | |
| download | linux-c1f4dea5bf9014e4733a738cfdaa8562e579715c.tar.gz linux-c1f4dea5bf9014e4733a738cfdaa8562e579715c.tar.bz2 linux-c1f4dea5bf9014e4733a738cfdaa8562e579715c.zip | |
x86/boot: Sanitize boot params before parsing command line
commit c00b413a96261faef4ce22329153c6abd4acef25 upstream.
The 5-level paging code parses the command line to look for the 'no5lvl'
string, and does so very early, before sanitize_boot_params() has been
called and has been given the opportunity to wipe bogus data from the
fields in boot_params that are not covered by struct setup_header, and
are therefore supposed to be initialized to zero by the bootloader.
This triggers an early boot crash when using syslinux-efi to boot a
recent kernel built with CONFIG_X86_5LEVEL=y and CONFIG_EFI_STUB=n, as
the 0xff padding that now fills the unused PE/COFF header is copied into
boot_params by the bootloader, and interpreted as the top half of the
command line pointer.
Fix this by sanitizing the boot_params before use. Note that there is no
harm in calling this more than once; subsequent invocations are able to
spot that the boot_params have already been cleaned up.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org> # v6.1+
Link: https://lore.kernel.org/r/20250306155915.342465-2-ardb+git@google.com
Closes: https://lore.kernel.org/all/202503041549.35913.ulrich.gemkow@ikr.uni-stuttgart.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/boot/compressed/pgtable_64.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c index c882e1f67af0..d8c5de40669d 100644 --- a/arch/x86/boot/compressed/pgtable_64.c +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include "misc.h" #include <asm/bootparam.h> +#include <asm/bootparam_utils.h> #include <asm/e820/types.h> #include <asm/processor.h> #include "pgtable.h" @@ -107,6 +108,7 @@ asmlinkage void configure_5level_paging(struct boot_params *bp, void *pgtable) bool l5_required = false; /* Initialize boot_params. Required for cmdline_find_option_bool(). */ + sanitize_boot_params(bp); boot_params_ptr = bp; /* |