gnu: upx: Fix CVE-2021-20285.

* gnu/packages/patches/upx-CVE-2021-20285.patch: New patch.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/compression.scm (upx): Apply patch.

1 files changed, 76 insertions, 0 deletions

diff --git a/gnu/packages/patches/upx-CVE-2021-20285.patch b/gnu/packages/patches/upx-CVE-2021-20285.patch
new file mode 100644
index 0000000000..1d47b2a8bb
--- /dev/null
+++ b/gnu/packages/patches/upx-CVE-2021-20285.patch
@@ -0,0 +1,76 @@
+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
+---
+ 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 182db192..3a4101cf 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);
+                                     }