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[PATCH] readelf, libdw: Guard against divide by zero line_range in .debug_line.
- From: Mark Wielaard <mjw at redhat dot com>
- To: elfutils-devel at lists dot fedorahosted dot org
- Date: Mon, 24 Nov 2014 23:39:59 +0100
- Subject: [PATCH] readelf, libdw: Guard against divide by zero line_range in .debug_line.
For DW_LNS_const_add_pc and special opcodes don't accept line_range
being zero.
Signed-off-by: Mark Wielaard <mjw@redhat.com>
---
libdw/ChangeLog | 5 +++++
libdw/dwarf_getsrclines.c | 6 ++++++
src/ChangeLog | 5 +++++
src/readelf.c | 7 +++++++
4 files changed, 23 insertions(+)
diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 2241c70..3e77994 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,8 @@
+2014-11-24 Mark Wielaard <mjw@redhat.com>
+
+ * dwarf_getsrclines.c (read_srclines): Check line_range is not zero
+ before usage.
+
2014-11-23 Mark Wielaard <mjw@redhat.com>
* dwarf_attr.c (dwarf_attr): Check __libdw_find_attr return value.
diff --git a/libdw/dwarf_getsrclines.c b/libdw/dwarf_getsrclines.c
index 15881e8..efdc00f 100644
--- a/libdw/dwarf_getsrclines.c
+++ b/libdw/dwarf_getsrclines.c
@@ -365,6 +365,9 @@ read_srclines (Dwarf *dbg,
/* Is this a special opcode? */
if (likely (opcode >= opcode_base))
{
+ if (line_range == 0)
+ goto invalid_data;
+
/* Yes. Handling this is quite easy since the opcode value
is computed with
@@ -576,6 +579,9 @@ read_srclines (Dwarf *dbg,
if (unlikely (standard_opcode_lengths[opcode] != 0))
goto invalid_data;
+ if (line_range == 0)
+ goto invalid_data;
+
advance_pc ((255 - opcode_base) / line_range);
break;
diff --git a/src/ChangeLog b/src/ChangeLog
index 19509dc..0082e65 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2014-11-24 Mark Wielaard <mjw@redhat.com>
+
+ * readelf.c (print_debug_line_section): Check line_range is not zero
+ before usage.
+
2014-11-23 Mark Wielaard <mjw@redhat.com>
* readelf.c (print_debug_aranges_section): Check length to catch
diff --git a/src/readelf.c b/src/readelf.c
index ffc14fd..7573898 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -6507,6 +6507,9 @@ print_debug_line_section (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr,
/* Is this a special opcode? */
if (likely (opcode >= opcode_base))
{
+ if (line_range == 0)
+ goto invalid_unit;
+
/* Yes. Handling this is quite easy since the opcode value
is computed with
@@ -6682,6 +6685,10 @@ print_debug_line_section (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr,
case DW_LNS_const_add_pc:
/* Takes no argument. */
+
+ if (line_range == 0)
+ goto invalid_unit;
+
advance_pc ((255 - opcode_base) / line_range);
{
char *a = format_dwarf_addr (dwflmod, 0, address, address);
--
1.9.3