From: Fabrice Fontaine Date: Wed, 31 Mar 2021 21:32:47 +0000 (+0200) Subject: package/upx: fix CVE-2021-20285 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=92a6db4fc686b6dd19577f737ceb5e46b82c92c7;p=buildroot.git package/upx: fix CVE-2021-20285 A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability. Signed-off-by: Fabrice Fontaine Signed-off-by: Peter Korsgaard --- diff --git a/package/upx/0001-Check-DT_REL-DT_RELA-DT_RELSZ-DT_RELASZ.patch b/package/upx/0001-Check-DT_REL-DT_RELA-DT_RELSZ-DT_RELASZ.patch new file mode 100644 index 0000000000..6fae9cac0e --- /dev/null +++ b/package/upx/0001-Check-DT_REL-DT_RELA-DT_RELSZ-DT_RELASZ.patch @@ -0,0 +1,80 @@ +From 3781df9da23840e596d5e9e8493f22666802fe6c Mon Sep 17 00:00:00 2001 +From: John Reiser +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 +--- + 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); + } diff --git a/package/upx/upx.mk b/package/upx/upx.mk index bdf5dd4c0e..e693a70db1 100644 --- a/package/upx/upx.mk +++ b/package/upx/upx.mk @@ -11,6 +11,9 @@ UPX_LICENSE = GPL-2.0+ UPX_LICENSE_FILES = COPYING UPX_CPE_ID_VENDOR = upx_project +# 0001-Check-DT_REL-DT_RELA-DT_RELSZ-DT_RELASZ.patch +UPX_IGNORE_CVES += CVE-2021-20285 + HOST_UPX_DEPENDENCIES = host-ucl host-zlib # We need to specify all, otherwise the default target only prints a message