From: Mark Wielaard <mark@klomp.org>
Date: Wed, 22 Feb 2023 22:34:00 +0000 (+0100)
Subject: libdw: Fix dwarf_getscopes memory leak on error
X-Git-Tag: elfutils-0.189~3
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e24d8a4a3ea106608bb3e8d33c4639cf71d0f08d;p=thirdparty%2Felfutils.git

libdw: Fix dwarf_getscopes memory leak on error

When there is an error in dwarf_getscopes after the initial scopes
have been allocated, e.g. when looking for the inlined scopes, then
the scopes would leak. Fix this by explicitly free the scopes on error.

https://sourceware.org/bugzilla/show_bug.cgi?id=29434

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

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 5e60f786d..406310ef3 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,8 @@
+2023-02-22  Mark Wielaard  <mark@klomp.org>
+
+	* dwarf_getscopes.c (origin_match): Don't free a->scopes.
+	(dwarf_getscopes): Free a->scopes on error.
+
 2023-02-20  Mark Wielaard  <mark@klomp.org>
 
 	* dwarf_begin_elf.c (check_section): Use elf_rawdata.
diff --git a/libdw/dwarf_getscopes.c b/libdw/dwarf_getscopes.c
index 833f1ac50..ce073b135 100644
--- a/libdw/dwarf_getscopes.c
+++ b/libdw/dwarf_getscopes.c
@@ -101,7 +101,7 @@ origin_match (unsigned int depth, struct Dwarf_Die_Chain *die, void *arg)
   Dwarf_Die *scopes = realloc (a->scopes, nscopes * sizeof scopes[0]);
   if (scopes == NULL)
     {
-      free (a->scopes);
+      /* a->scopes will be freed by dwarf_getscopes on error.  */
       __libdw_seterrno (DWARF_E_NOMEM);
       return -1;
     }
@@ -200,6 +200,8 @@ dwarf_getscopes (Dwarf_Die *cudie, Dwarf_Addr pc, Dwarf_Die **scopes)
 
   if (result > 0)
     *scopes = a.scopes;
+  else if (result < 0)
+    free (a.scopes);
 
   return result;
 }