jory/upx
1
0
Fork 0
Code Issues Pull Requests 1 Actions Packages Projects Releases Wiki Activity

Detect bogus DT_SYMENT.

Browse Source 
https://github.com/upx/upx/issues/331
	modified:   p_lx_elf.cpp
This commit is contained in:
John Reiser
2020-01-13 17:10:02 -08:00
parent 0f4975fd7f
commit eb90eab632
1 changed files with 16 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/p_lx_elf.cpp
+16
View File
@@ -1614,9 +1614,17 @@ PackLinuxElf32::invert_pt_dynamic(Elf32_Dyn const *dynp)
unsigned const z_sym = dt_table[Elf32_Dyn::DT_SYMENT]; unsigned const z_sym = dt_table[Elf32_Dyn::DT_SYMENT];
unsigned const sz_sym = !z_sym ? sizeof(Elf32_Sym) unsigned const sz_sym = !z_sym ? sizeof(Elf32_Sym)
: get_te32(&dynp0[-1+ z_sym].d_val); : get_te32(&dynp0[-1+ z_sym].d_val);
if (sz_sym < sizeof(Elf32_Sym)) {
char msg[50]; snprintf(msg, sizeof(msg),
"bad DT_SYMENT %x", sz_sym);
throwCantPack(msg);
}
if (v_sym < v_str) { if (v_sym < v_str) {
symnum_end = (v_str - v_sym) / sz_sym; symnum_end = (v_str - v_sym) / sz_sym;
} }
if (symnum_end < 1) {
throwCantPack("bad DT_SYMTAB");
}
} }
// DT_HASH often ends at DT_SYMTAB // DT_HASH often ends at DT_SYMTAB
unsigned const v_hsh = elf_unsigned_dynamic(Elf32_Dyn::DT_HASH); unsigned const v_hsh = elf_unsigned_dynamic(Elf32_Dyn::DT_HASH);
@@ -5104,9 +5112,17 @@ PackLinuxElf64::invert_pt_dynamic(Elf64_Dyn const *dynp)
unsigned const z_sym = dt_table[Elf64_Dyn::DT_SYMENT]; unsigned const z_sym = dt_table[Elf64_Dyn::DT_SYMENT];
unsigned const sz_sym = !z_sym ? sizeof(Elf64_Sym) unsigned const sz_sym = !z_sym ? sizeof(Elf64_Sym)
: get_te64(&dynp0[-1+ z_sym].d_val); : get_te64(&dynp0[-1+ z_sym].d_val);
if (sz_sym < sizeof(Elf64_Sym)) {
char msg[50]; snprintf(msg, sizeof(msg),
"bad DT_SYMENT %x", sz_sym);
throwCantPack(msg);
}
if (v_sym < v_str) { if (v_sym < v_str) {
symnum_end = (v_str - v_sym) / sz_sym; symnum_end = (v_str - v_sym) / sz_sym;
} }
if (symnum_end < 1) {
throwCantPack("bad DT_SYMTAB");
}
} }
// DT_HASH often ends at DT_SYMTAB // DT_HASH often ends at DT_SYMTAB
unsigned const v_hsh = elf_unsigned_dynamic(Elf64_Dyn::DT_HASH); unsigned const v_hsh = elf_unsigned_dynamic(Elf64_Dyn::DT_HASH);