From: Mark Wielaard <mark@klomp.org>
Date: Wed, 16 Jan 2019 10:57:35 +0000 (+0100)
Subject: libebl: Check GNU property note pr_datasz fits inside note description.
X-Git-Tag: elfutils-0.176~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=012018907ca05eb0ab51d424a596ef38fc87cae1;p=thirdparty%2Felfutils.git

libebl: Check GNU property note pr_datasz fits inside note description.

Before printing the data values, make sure pr_datasz doesn't go beyond
the end of the note description data.

https://sourceware.org/bugzilla/show_bug.cgi?id=24075

Signed-off-by: Mark Wielaard <mark@klomp.org>
---

diff --git a/libebl/ChangeLog b/libebl/ChangeLog
index 0174f331a..77c22746e 100644
--- a/libebl/ChangeLog
+++ b/libebl/ChangeLog
@@ -1,3 +1,7 @@
+2019-01-16  Mark Wielaard  <mark@klomp.org>
+
+	* eblobjnte.c (ebl_object_note): Check pr_datasz isn't too large.
+
 2018-12-02  Mark Wielaard  <mark@klomp.org>
 
 	* eblobjnte.c (ebl_object_note): For GNU_PROPERTY_STACK_SIZE use
diff --git a/libebl/eblobjnote.c b/libebl/eblobjnote.c
index c19ea37fc..9094715c9 100644
--- a/libebl/eblobjnote.c
+++ b/libebl/eblobjnote.c
@@ -350,6 +350,13 @@ ebl_object_note (Ebl *ebl, uint32_t namesz, const char *name, uint32_t type,
 		  desc += 8;
 		  descsz -= 8;
 
+		  if (prop.pr_datasz > descsz)
+		    {
+		      printf ("BAD property datasz: %" PRId32 "\n",
+			      prop.pr_datasz);
+		      return;
+		    }
+
 		  int elfclass = gelf_getclass (ebl->elf);
 		  char *elfident = elf_getident (ebl->elf, NULL);
 		  GElf_Ehdr ehdr;