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Stronger test and better message for PT_LOAD[0].p_offset != 0

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https://github.com/upx/upx/issues/80
	modified:   p_lx_elf.cpp
This commit is contained in:
John Reiser
2017-03-31 12:20:02 -07:00
parent 0e511c3e07
commit 12e5703541
1 changed files with 67 additions and 66 deletions
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src/p_lx_elf.cpp
+42 -41
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@@ -1515,18 +1515,17 @@ bool PackLinuxElf32::canPack()
} }
unsigned const p_type = get_te32(&phdr->p_type); unsigned const p_type = get_te32(&phdr->p_type);
unsigned const p_offset = get_te32(&phdr->p_offset); unsigned const p_offset = get_te32(&phdr->p_offset);
if (1!=exetype && phdr->PT_LOAD32 == p_type) { if (1!=exetype && phdr->PT_LOAD32 == p_type) { // 1st PT_LOAD
exetype = 1; exetype = 1;
load_va = get_te32(&phdr->p_vaddr); load_va = get_te32(&phdr->p_vaddr); // class data member
unsigned file_offset = get_te32(&phdr->p_offset); unsigned const off = ~page_mask & load_va;
if (~(upx_uint64_t)page_mask & file_offset) { if (off && off == p_offset) { // specific hint
if ((~page_mask & (unsigned)load_va) == file_offset) {
throwCantPack("Go-language PT_LOAD: try hemfix.c, or try '--force-execve'"); throwCantPack("Go-language PT_LOAD: try hemfix.c, or try '--force-execve'");
// Fixing it inside upx fails because packExtent() reads original file. // Fixing it inside upx fails because packExtent() reads original file.
return false;
} }
else { if (0 != p_offset) { // 1st PT_LOAD must cover Ehdr and Phdr
throwCantPack("invalid Phdr p_offset; try '--force-execve'"); throwCantPack("first PT_LOAD.p_offset != 0; try '--force-execve'");
}
return false; return false;
} }
} }
@@ -1537,9 +1536,7 @@ bool PackLinuxElf32::canPack()
throwCantPack("PT_NOTEs too big; try '--force-execve'"); throwCantPack("PT_NOTEs too big; try '--force-execve'");
return false; return false;
} }
} if (osabi_note && Elf32_Ehdr::ELFOSABI_NONE==osabi0) { // Still seems to be generic.
if (Elf32_Ehdr::ELFOSABI_NONE==osabi0 // Still seems to be generic.
&& NULL!=osabi_note && phdr->PT_NOTE == p_type) {
struct { struct {
struct Elf32_Nhdr nhdr; struct Elf32_Nhdr nhdr;
char name[8]; char name[8];
@@ -1559,6 +1556,7 @@ bool PackLinuxElf32::canPack()
} }
} }
} }
}
if (Elf32_Ehdr::ELFOSABI_NONE ==osabi0 if (Elf32_Ehdr::ELFOSABI_NONE ==osabi0
|| Elf32_Ehdr::ELFOSABI_LINUX==osabi0) { // No EI_OSBAI, no PT_NOTE. || Elf32_Ehdr::ELFOSABI_LINUX==osabi0) { // No EI_OSBAI, no PT_NOTE.
unsigned const arm_eabi = 0xff000000u & get_te32(&ehdr->e_flags); unsigned const arm_eabi = 0xff000000u & get_te32(&ehdr->e_flags);
@@ -1723,20 +1721,21 @@ PackLinuxElf64ppcle::canPack()
for (unsigned j=0; j < e_phnum; ++phdr, ++j) { for (unsigned j=0; j < e_phnum; ++phdr, ++j) {
if (j >= 14) if (j >= 14)
return false; return false;
if (phdr->PT_LOAD64 == get_te32(&phdr->p_type)) { unsigned const p_type = get_te32(&phdr->p_type);
load_va = get_te64(&phdr->p_vaddr); if (1!=exetype && phdr->PT_LOAD64 == p_type) { // 1st PT_LOAD
upx_uint64_t file_offset = get_te64(&phdr->p_offset); exetype = 1;
if (~page_mask & file_offset) { load_va = get_te64(&phdr->p_vaddr); // class data member
if ((~page_mask & load_va) == file_offset) { upx_uint64_t const p_offset = get_te64(&phdr->p_offset);
upx_uint64_t const off = ~page_mask & load_va;
if (off && off == p_offset) { // specific hint
throwCantPack("Go-language PT_LOAD: try hemfix.c, or try '--force-execve'"); throwCantPack("Go-language PT_LOAD: try hemfix.c, or try '--force-execve'");
// Fixing it inside upx fails because packExtent() reads original file. // Fixing it inside upx fails because packExtent() reads original file.
}
else {
throwCantPack("invalid Phdr p_offset; try '--force-execve'");
}
return false; return false;
} }
exetype = 1; if (0 != p_offset) { // 1st PT_LOAD must cover Ehdr and Phdr
throwCantPack("first PT_LOAD.p_offset != 0; try '--force-execve'");
return false;
}
break; break;
} }
} }
@@ -1916,20 +1915,21 @@ PackLinuxElf64amd::canPack()
for (unsigned j=0; j < e_phnum; ++phdr, ++j) { for (unsigned j=0; j < e_phnum; ++phdr, ++j) {
if (j >= 14) if (j >= 14)
return false; return false;
if (phdr->PT_LOAD64 == get_te32(&phdr->p_type)) { unsigned const p_type = get_te32(&phdr->p_type);
load_va = get_te64(&phdr->p_vaddr); if (1!=exetype && phdr->PT_LOAD64 == p_type) { // 1st PT_LOAD
upx_uint64_t file_offset = get_te64(&phdr->p_offset); exetype = 1;
if (~page_mask & file_offset) { load_va = get_te64(&phdr->p_vaddr); // class data member
if ((~page_mask & load_va) == file_offset) { upx_uint64_t const p_offset = get_te64(&phdr->p_offset);
upx_uint64_t const off = ~page_mask & load_va;
if (off && off == p_offset) { // specific hint
throwCantPack("Go-language PT_LOAD: try hemfix.c, or try '--force-execve'"); throwCantPack("Go-language PT_LOAD: try hemfix.c, or try '--force-execve'");
// Fixing it inside upx fails because packExtent() reads original file. // Fixing it inside upx fails because packExtent() reads original file.
}
else {
throwCantPack("invalid Phdr p_offset; try '--force-execve'");
}
return false; return false;
} }
exetype = 1; if (0 != p_offset) { // 1st PT_LOAD must cover Ehdr and Phdr
throwCantPack("first PT_LOAD.p_offset != 0; try '--force-execve'");
return false;
}
break; break;
} }
} }
@@ -2110,20 +2110,21 @@ PackLinuxElf64arm::canPack()
for (unsigned j=0; j < e_phnum; ++phdr, ++j) { for (unsigned j=0; j < e_phnum; ++phdr, ++j) {
if (j >= 14) if (j >= 14)
return false; return false;
if (phdr->PT_LOAD64 == get_te32(&phdr->p_type)) { unsigned const p_type = get_te32(&phdr->p_type);
load_va = get_te64(&phdr->p_vaddr); if (1!=exetype && phdr->PT_LOAD64 == p_type) { // 1st PT_LOAD
upx_uint64_t file_offset = get_te64(&phdr->p_offset); exetype = 1;
if (~page_mask & file_offset) { load_va = get_te64(&phdr->p_vaddr); // class data member
if ((~page_mask & load_va) == file_offset) { upx_uint64_t const p_offset = get_te64(&phdr->p_offset);
upx_uint64_t const off = ~page_mask & load_va;
if (off && off == p_offset) { // specific hint
throwCantPack("Go-language PT_LOAD: try hemfix.c, or try '--force-execve'"); throwCantPack("Go-language PT_LOAD: try hemfix.c, or try '--force-execve'");
// Fixing it inside upx fails because packExtent() reads original file. // Fixing it inside upx fails because packExtent() reads original file.
}
else {
throwCantPack("invalid Phdr p_offset; try '--force-execve'");
}
return false; return false;
} }
exetype = 1; if (0 != p_offset) { // 1st PT_LOAD must cover Ehdr and Phdr
throwCantPack("first PT_LOAD.p_offset != 0; try '--force-execve'");
return false;
}
break; break;
} }
} }