shim-unsigned-x64/SOURCES/0015-Fix-for-Section-0-has-negative-size-error-when-loadi.patch
2021-10-08 16:45:45 +00:00

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4.5 KiB
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From 3d04aef8d80293d701f7efee6b5300f9f528ddfc Mon Sep 17 00:00:00 2001
From: Maran Wilson <maran.wilson@oracle.com>
Date: Tue, 7 Aug 2018 15:32:29 -0700
Subject: [PATCH 15/62] Fix for "Section 0 has negative size" error when
loading fbaa64.efi
The current code is incorrectly failing to load the fbaa64.efi image found
in Arm servers even though the UEFI shell code is able to properly load
and execute the same image.
The problem is due to the presence of a section header that has zero size
and address and marked "discardable" in the fbaa64.efi image.
Although there is already a check further down in the code to look for
the discardable bit and skip further verification checks if set, we never
get to that point due to the "end < base" check at the start of the loop.
Here is a dump of the fbaa64.efi image as compiled on an Arm machine
from the latest code in this repo:
% # First I used hexedit to change header byte from 'AA' to '86'
% # so that objdump was able to correctly parse the file:
% objdump -x -m aarch64 fbaa64.efi
fbaa64.efi: file format pei-x86-64
fbaa64.efi
architecture: i386:x86-64, flags 0x00000103:
HAS_RELOC, EXEC_P, D_PAGED
start address 0x0000000000000148
Characteristics 0x20e
executable
line numbers stripped
symbols stripped
debugging information removed
Time/Date Wed Dec 31 16:00:00 1969
Magic 020b (PE32+)
MajorLinkerVersion 2
MinorLinkerVersion 20
SizeOfCode 000b15d0
SizeOfInitializedData 00000000
SizeOfUninitializedData 00000000
AddressOfEntryPoint 0000000000000148
BaseOfCode 0000000000000148
ImageBase 0000000000000000
SectionAlignment 0000000000000020
FileAlignment 0000000000000008
MajorOSystemVersion 0
MinorOSystemVersion 0
MajorImageVersion 0
MinorImageVersion 0
MajorSubsystemVersion 0
MinorSubsystemVersion 0
Win32Version 00000000
SizeOfImage 000b1718
SizeOfHeaders 00000148
CheckSum 00000000
Subsystem 0000000a (EFI application)
DllCharacteristics 00000000
SizeOfStackReserve 0000000000000000
SizeOfStackCommit 0000000000000000
SizeOfHeapReserve 0000000000000000
SizeOfHeapCommit 0000000000000000
LoaderFlags 00000000
NumberOfRvaAndSizes 00000006
The Data Directory
Entry 0 0000000000000000 00000000 Export Directory [.edata (or where ever we found it)]
Entry 1 0000000000000000 00000000 Import Directory [parts of .idata]
Entry 2 0000000000000000 00000000 Resource Directory [.rsrc]
Entry 3 0000000000000000 00000000 Exception Directory [.pdata]
Entry 4 0000000000000000 00000000 Security Directory
Entry 5 0000000000000000 00000000 Base Relocation Directory [.reloc]
Entry 6 0000000000000000 00000000 Debug Directory
Entry 7 0000000000000000 00000000 Description Directory
Entry 8 0000000000000000 00000000 Special Directory
Entry 9 0000000000000000 00000000 Thread Storage Directory [.tls]
Entry a 0000000000000000 00000000 Load Configuration Directory
Entry b 0000000000000000 00000000 Bound Import Directory
Entry c 0000000000000000 00000000 Import Address Table Directory
Entry d 0000000000000000 00000000 Delay Import Directory
Entry e 0000000000000000 00000000 CLR Runtime Header
Entry f 0000000000000000 00000000 Reserved
Sections:
Idx Name Size VMA LMA File off Algn
0 .reloc 00000000 0000000000000000 0000000000000000 00000000 2**0
ALLOC, LOAD, READONLY, DATA
1 .text 000b15d0 0000000000000148 0000000000000148 00000148 2**4
CONTENTS, ALLOC, LOAD, CODE
SYMBOL TABLE:
no symbols
Signed-off-by: Maran Wilson <maran.wilson@oracle.com>
Reviewed-by: Aaron Young <aaron.young@oracle.com>
Reviewed-by: Jack Schwartz <jack.schwartz@oracle.com>
Upstream-commit-id: 6df7a8f5609
---
shim.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/shim.c b/shim.c
index ae03da7eddf..d980cadacfc 100644
--- a/shim.c
+++ b/shim.c
@@ -1347,6 +1347,11 @@ static EFI_STATUS handle_image (void *data, unsigned int datasize,
*/
Section = context.FirstSection;
for (i = 0; i < context.NumberOfSections; i++, Section++) {
+ /* Don't try to copy discardable sections with zero size */
+ if ((Section->Characteristics & EFI_IMAGE_SCN_MEM_DISCARDABLE) &&
+ !Section->Misc.VirtualSize)
+ continue;
+
base = ImageAddress (buffer, context.ImageSize,
Section->VirtualAddress);
end = ImageAddress (buffer, context.ImageSize,
--
2.26.2