elfutils: Backport fix for CVE-2021-33294

Upstream-Status: Backport from https://sourceware.org/git/?p=elfutils.git;a=commit;h=480b6fa3662ba8ffeee274bf0d37423413c01e55

Reference
https://nvd.nist.gov/vuln/detail/CVE-2021-33294
https://sourceware.org/bugzilla/show_bug.cgi?id=27501

(From OE-Core rev: 9cd6fea32edf8e4da0c33547e1df6d1ec81b350d)

Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 73 insertions, 0 deletions

diff --git a/meta/recipes-devtools/elfutils/elfutils_0.178.bb b/meta/recipes-devtools/elfutils/elfutils_0.178.bb
index 97d033e356..29a3bbfffb 100644
--- a/meta/recipes-devtools/elfutils/elfutils_0.178.bb
+++ b/meta/recipes-devtools/elfutils/elfutils_0.178.bb
@@ -34,6 +34,7 @@ SRC_URI = "https://sourceware.org/elfutils/ftp/${PV}/${BP}.tar.bz2 \
            file://0001-ppc_initreg.c-Incliude-asm-ptrace.h-for-pt_regs-defi.patch \
            file://run-ptest \
            file://ptest.patch \
+           file://CVE-2021-33294.patch \
            "
 SRC_URI_append_libc-musl = " \
            file://0001-musl-obstack-fts.patch \
diff --git a/meta/recipes-devtools/elfutils/files/CVE-2021-33294.patch b/meta/recipes-devtools/elfutils/files/CVE-2021-33294.patch
new file mode 100644
index 0000000000..0500a4cf83
--- /dev/null
+++ b/meta/recipes-devtools/elfutils/files/CVE-2021-33294.patch
@@ -0,0 +1,72 @@
+From 480b6fa3662ba8ffeee274bf0d37423413c01e55 Mon Sep 17 00:00:00 2001
+From: Mark Wielaard <mark@klomp.org>
+Date: Wed, 3 Mar 2021 21:40:53 +0100
+Subject: [PATCH] readelf: Sanity check verneed and verdef offsets in handle_symtab.
+
+We are going through vna_next, vn_next and vd_next in a while loop.
+Make sure that all offsets are sane. We don't want things to wrap
+around so we go in cycles.
+
+https://sourceware.org/bugzilla/show_bug.cgi?id=27501
+
+Signed-off-by: Mark Wielaard <mark@klomp.org>
+
+Upstream-Status: Backport [https://sourceware.org/git/?p=elfutils.git;a=commit;h=480b6fa3662ba8ffeee274bf0d37423413c01e55]
+CVE: CVE-2021-33294
+Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
+---
+ src/ChangeLog |  5 +++++
+ src/readelf.c | 10 +++++++++-
+ 2 files changed, 14 insertions(+), 1 deletion(-)
+
+diff --git a/src/ChangeLog b/src/ChangeLog
+index 6af977e..f0d9e39 100644
+--- a/src/ChangeLog
++++ b/src/ChangeLog
+@@ -1,3 +1,8 @@
++2021-03-03  Mark Wielaard  <mark@klomp.org>
++
++       * readelf.c (handle_symtab): Sanity check verneed vna_next,
++       vn_next and verdef vd_next offsets.
++
+ 2019-11-26  Mark Wielaard  <mark@klomp.org>
+ 
+        * Makefile.am (BUILD_STATIC): Add libraries needed for libdw.
+diff --git a/src/readelf.c b/src/readelf.c
+index 5994615..ab7a1c1 100644
+--- a/src/readelf.c
++++ b/src/readelf.c
+@@ -2550,7 +2550,9 @@ handle_symtab (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr)
+                                                 &vernaux_mem);
+                      while (vernaux != NULL
+                             && vernaux->vna_other != *versym
+-                            && vernaux->vna_next != 0)
++                            && vernaux->vna_next != 0
++                            && (verneed_data->d_size - vna_offset
++                                >= vernaux->vna_next))
+                        {
+                          /* Update the offset.  */
+                          vna_offset += vernaux->vna_next;
+@@ -2567,6 +2569,9 @@ handle_symtab (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr)
+                        /* Found it.  */
+                        break;
+ 
++                     if (verneed_data->d_size - vn_offset < verneed->vn_next)
++                       break;
++
+                      vn_offset += verneed->vn_next;
+                      verneed = (verneed->vn_next == 0
+                                 ? NULL
+@@ -2602,6 +2607,9 @@ handle_symtab (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr)
+                        /* Found the definition.  */
+                        break;
+ 
++                     if (verdef_data->d_size - vd_offset < verdef->vd_next)
++                       break;
++
+                      vd_offset += verdef->vd_next;
+                      verdef = (verdef->vd_next == 0
+                                ? NULL
+-- 
+2.25.1
+