Found by the afl fuzzer. The next offset (after a locview) comes from a
DIE loclist attribute. This could be a bogus value so large it overflows
the buffer and makes us print past the end of buffer.
Signed-off-by: Mark Wielaard <m...@klomp.org>
---
src/ChangeLog | 5 +++++
src/readelf.c | 4 +++-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/ChangeLog b/src/ChangeLog
index 5f381cf..3d266e2 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2018-06-16 Mark Wielaard <m...@klomp.org>
+
+ * readelf.c (print_debug_loc_section): Make sure next_off doesn't
+ overflow d_buf.
+
2018-06-13 Mark Wielaard <m...@klomp.org>
* readelf.c (die_type_sign_bytes): New function.
diff --git a/src/readelf.c b/src/readelf.c
index 5e7061d..2e7378e 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -9310,7 +9310,9 @@ print_debug_loc_section (Dwfl_Module *dwflmod,
listptr_idx);
const unsigned char *locp = readp;
const unsigned char *locendp;
- if (next_off == 0)
+ if (next_off == 0
+ || next_off > (size_t) (endp
+ - (const unsigned char *) data->d_buf))
locendp = endp;
else
locendp = (const unsigned char *) data->d_buf + next_off;
--
1.8.3.1
