File libdw-check-end-of-attributes-list-consistently.patch of Package elfutils.8903
From 6983e59b727458a6c64d9659c85f08218bc4fcda Mon Sep 17 00:00:00 2001
From: Mark Wielaard <email@example.com>
Date: Sat, 18 Aug 2018 19:51:27 +0200
Subject: [PATCH] libdw: Check end of attributes list consistently.
dwarf_child (__libdw_find_attr), dwarf_getabbrevattr[_data] and
dwarf_getattrs all assume the end of the attribute list is when
both the name (code) and form of the attribute are zero.
dwarf_getabbrev (__libdw_getabbrev) and dwarf_hasattr assume the
end of the attribute list is when either the name (code) or the
form of the attribute is zero.
The DWARF spec says: "The series of attribute specifications ends
with an entry containing 0 for the name and 0 for the form." So
the first check is correct.
Make sure dwarf_getabbrev and dwarf_hasattr use the same check.
This is important since all other functions expect dwarf_getabbrev
(__libdw_getabbrev) to have done a data sanity check of the attribute.
So if the ending condition is different it could cause a crash.
elfutils packaging edits:
- hunk#1 in dwarf_getabbrev.c backported from original patch
- changelog hunk removed from original patch to avoid conflict
Signed-off-by: Mark Wielaard <firstname.lastname@example.org>
Signed-off-by: Joao Moreira <email@example.com>
libdw/ChangeLog | 7 +++++++
libdw/dwarf_getabbrev.c | 2 +-
libdw/dwarf_hasattr.c | 4 ++--
3 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/libdw/dwarf_getabbrev.c b/libdw/dwarf_getabbrev.c
index 988d12c..6a7e981 100644
@@ -134,7 +134,7 @@
get_uleb128 (attrform, abbrevp, end);
- while (attrname != 0 && attrform != 0 && ++abb->attrcnt);
+ while ((attrname != 0 || attrform != 0) && ++abb->attrcnt);
/* Return the length to the caller if she asked for it. */
if (lengthp != NULL)
diff --git a/libdw/dwarf_hasattr.c b/libdw/dwarf_hasattr.c
index 90053b1..eca0839 100644
@@ -72,8 +72,8 @@ dwarf_hasattr (Dwarf_Die *die, unsigned int search_name)
get_uleb128 (attr_form, attrp, endp);
- /* We can stop if we found the attribute with value zero. */
- if (attr_name == 0 || attr_form == 0)
+ /* We can stop if we found the end of the attribute list. */
+ if (attr_name == 0 && attr_form == 0)
if (attr_name == search_name)