6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ard Biesheuvel ardb@kernel.org
[ Commit 34951f3c28bdf6481d949a20413b2ce7693687b2 upstream ]
Describe the code and data of the decompressor binary using separate .text and .data PE/COFF sections, so that we will be able to map them using restricted permissions once we increase the section and file alignment sufficiently. This avoids the need for memory mappings that are writable and executable at the same time, which is something that is best avoided for security reasons.
Signed-off-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Ingo Molnar mingo@kernel.org Link: https://lore.kernel.org/r/20230915171623.655440-17-ardb@google.com Signed-off-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/boot/Makefile | 2 +- arch/x86/boot/header.S | 19 +++++++++++++++---- 2 files changed, 16 insertions(+), 5 deletions(-)
--- a/arch/x86/boot/Makefile +++ b/arch/x86/boot/Makefile @@ -91,7 +91,7 @@ $(obj)/vmlinux.bin: $(obj)/compressed/vm
SETUP_OBJS = $(addprefix $(obj)/,$(setup-y))
-sed-zoffset := -e 's/^([0-9a-fA-F]*) [a-zA-Z] (startup_32|efi.._stub_entry|efi(32)?_pe_entry|input_data|kernel_info|_end|_ehead|_text|_edata|z_.*)$$/#define ZO_\2 0x\1/p' +sed-zoffset := -e 's/^([0-9a-fA-F]*) [a-zA-Z] (startup_32|efi.._stub_entry|efi(32)?_pe_entry|input_data|kernel_info|_end|_ehead|_text|_e?data|z_.*)$$/#define ZO_\2 0x\1/p'
quiet_cmd_zoffset = ZOFFSET $@ cmd_zoffset = $(NM) $< | sed -n $(sed-zoffset) > $@ --- a/arch/x86/boot/header.S +++ b/arch/x86/boot/header.S @@ -74,9 +74,9 @@ optional_header: .byte 0x02 # MajorLinkerVersion .byte 0x14 # MinorLinkerVersion
- .long setup_size + ZO__end - 0x200 # SizeOfCode + .long ZO__data # SizeOfCode
- .long 0 # SizeOfInitializedData + .long ZO__end - ZO__data # SizeOfInitializedData .long 0 # SizeOfUninitializedData
.long setup_size + ZO_efi_pe_entry # AddressOfEntryPoint @@ -177,9 +177,9 @@ section_table: .byte 0 .byte 0 .byte 0 - .long ZO__end + .long ZO__data .long setup_size - .long ZO__edata # Size of initialized data + .long ZO__data # Size of initialized data # on disk .long setup_size .long 0 # PointerToRelocations @@ -190,6 +190,17 @@ section_table: IMAGE_SCN_MEM_READ | \ IMAGE_SCN_MEM_EXECUTE # Characteristics
+ .ascii ".data\0\0\0" + .long ZO__end - ZO__data # VirtualSize + .long setup_size + ZO__data # VirtualAddress + .long ZO__edata - ZO__data # SizeOfRawData + .long setup_size + ZO__data # PointerToRawData + + .long 0, 0, 0 + .long IMAGE_SCN_CNT_INITIALIZED_DATA | \ + IMAGE_SCN_MEM_READ | \ + IMAGE_SCN_MEM_WRITE # Characteristics + .set section_count, (. - section_table) / 40 #endif /* CONFIG_EFI_STUB */