| From 3781df9da23840e596d5e9e8493f22666802fe6c Mon Sep 17 00:00:00 2001 |
| From: John Reiser <jreiser@BitWagon.com> |
| Date: Fri, 11 Dec 2020 13:38:18 -0800 |
| Subject: [PATCH] Check DT_REL/DT_RELA, DT_RELSZ/DT_RELASZ |
| |
| https://github.com/upx/upx/issues/421 |
| modified: p_lx_elf.cpp |
| |
| [Retrieved from: |
| https://github.com/upx/upx/commit/3781df9da23840e596d5e9e8493f22666802fe6c] |
| Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com> |
| --- |
| src/p_lx_elf.cpp | 34 +++++++++++++++++++++++++++++----- |
| 1 file changed, 29 insertions(+), 5 deletions(-) |
| |
| diff --git a/src/p_lx_elf.cpp b/src/p_lx_elf.cpp |
| index 182db192f..3a4101cf7 100644 |
| --- a/src/p_lx_elf.cpp |
| +++ b/src/p_lx_elf.cpp |
| @@ -2222,8 +2222,20 @@ bool PackLinuxElf32::canPack() |
| int z_rsz = dt_table[Elf32_Dyn::DT_RELSZ]; |
| if (z_rel && z_rsz) { |
| unsigned rel_off = get_te32(&dynseg[-1+ z_rel].d_val); |
| + if ((unsigned)file_size <= rel_off) { |
| + char msg[70]; snprintf(msg, sizeof(msg), |
| + "bad Elf32_Dynamic[DT_REL] %#x\n", |
| + rel_off); |
| + throwCantPack(msg); |
| + } |
| Elf32_Rel *rp = (Elf32_Rel *)&file_image[rel_off]; |
| unsigned relsz = get_te32(&dynseg[-1+ z_rsz].d_val); |
| + if ((unsigned)file_size <= relsz) { |
| + char msg[70]; snprintf(msg, sizeof(msg), |
| + "bad Elf32_Dynamic[DT_RELSZ] %#x\n", |
| + relsz); |
| + throwCantPack(msg); |
| + } |
| Elf32_Rel *last = (Elf32_Rel *)(relsz + (char *)rp); |
| for (; rp < last; ++rp) { |
| unsigned r_va = get_te32(&rp->r_offset); |
| @@ -2562,14 +2574,26 @@ PackLinuxElf64::canPack() |
| int z_rel = dt_table[Elf64_Dyn::DT_RELA]; |
| int z_rsz = dt_table[Elf64_Dyn::DT_RELASZ]; |
| if (z_rel && z_rsz) { |
| - unsigned rel_off = get_te64(&dynseg[-1+ z_rel].d_val); |
| + upx_uint64_t rel_off = get_te64(&dynseg[-1+ z_rel].d_val); |
| + if ((u64_t)file_size <= rel_off) { |
| + char msg[70]; snprintf(msg, sizeof(msg), |
| + "bad Elf64_Dynamic[DT_RELA] %#llx\n", |
| + rel_off); |
| + throwCantPack(msg); |
| + } |
| Elf64_Rela *rp = (Elf64_Rela *)&file_image[rel_off]; |
| - unsigned relsz = get_te64(&dynseg[-1+ z_rsz].d_val); |
| + upx_uint64_t relsz = get_te64(&dynseg[-1+ z_rsz].d_val); |
| + if ((u64_t)file_size <= relsz) { |
| + char msg[70]; snprintf(msg, sizeof(msg), |
| + "bad Elf64_Dynamic[DT_RELASZ] %#llx\n", |
| + relsz); |
| + throwCantPack(msg); |
| + } |
| Elf64_Rela *last = (Elf64_Rela *)(relsz + (char *)rp); |
| for (; rp < last; ++rp) { |
| - unsigned r_va = get_te64(&rp->r_offset); |
| + upx_uint64_t r_va = get_te64(&rp->r_offset); |
| if (r_va == user_init_ava) { // found the Elf64_Rela |
| - unsigned r_info = get_te64(&rp->r_info); |
| + upx_uint64_t r_info = get_te64(&rp->r_info); |
| unsigned r_type = ELF64_R_TYPE(r_info); |
| if (Elf64_Ehdr::EM_AARCH64 == e_machine |
| && R_AARCH64_RELATIVE == r_type) { |
| @@ -2581,7 +2605,7 @@ PackLinuxElf64::canPack() |
| } |
| else { |
| char msg[50]; snprintf(msg, sizeof(msg), |
| - "bad relocation %#x DT_INIT_ARRAY[0]", |
| + "bad relocation %#llx DT_INIT_ARRAY[0]", |
| r_info); |
| throwCantPack(msg); |
| } |
