Re: [PATCH] libdwfl: Fix memory leak in link_map.c dwfl_link_map_report.

Re: [PATCH] libdwfl: Fix memory leak in link_map.c dwfl_link_map_report.

[Mark Wielaard]

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On Tue, Dec 01, 2015 at 11:17:22PM +0100, Mark Wielaard wrote:
> The phdrs buffer could come from the core file or through the executable.
> dwfl_link_map_report would leak the buffer if it came from the executable.
> Track where the buffer came from and free appropriately.

Pushed to master.

[PATCH] libdwfl: Fix memory leak in link_map.c dwfl_link_map_report.

[Mark Wielaard]

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The phdrs buffer could come from the core file or through the executable.
dwfl_link_map_report would leak the buffer if it came from the executable.
Track where the buffer came from and free appropriately.

Signed-off-by: Mark Wielaard <mjw@redhat.com>
---
 libdwfl/ChangeLog  | 5 +++++
 libdwfl/link_map.c | 9 +++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog
index 9640b4f..30a5205 100644
--- a/libdwfl/ChangeLog
+++ b/libdwfl/ChangeLog
@@ -1,5 +1,10 @@
 2015-12-01  Mark Wielaard  <mjw@redhat.com>
 
+	* link_map.c (dwfl_link_map_report): Track whether in.d_buf comes
+	from exec or memory_callback, free as appropriate.
+
+2015-12-01  Mark Wielaard  <mjw@redhat.com>
+
 	* libdwflP.h (struct Dwfl_User_Core): New.
 	(struct DWfl): Replace executable_for_core with user_core.
 	* argp-std.c (parse_opt): Store core and fd in Dwfl user_core.
diff --git a/libdwfl/link_map.c b/libdwfl/link_map.c
index e73b219..2bc0400 100644
--- a/libdwfl/link_map.c
+++ b/libdwfl/link_map.c
@@ -791,6 +791,7 @@ dwfl_link_map_report (Dwfl *dwfl, const void *auxv, size_t auxv_size,
 	  bool in_ok = (*memory_callback) (dwfl, phdr_segndx, &in.d_buf,
 					   &in.d_size, phdr, phnum * phent,
 					   memory_callback_arg);
+	  bool in_from_exec = false;
 	  if (! in_ok
 	      && dwfl->user_core != NULL
 	      && dwfl->user_core->executable_for_core != NULL)
@@ -855,6 +856,7 @@ dwfl_link_map_report (Dwfl *dwfl, const void *auxv, size_t auxv_size,
 		  return false;
 		}
 	      in_ok = true;
+	      in_from_exec = true;
 	    }
 	  if (in_ok)
 	    {
@@ -903,8 +905,11 @@ dwfl_link_map_report (Dwfl *dwfl, const void *auxv, size_t auxv_size,
 		    }
 		}
 
-	      (*memory_callback) (dwfl, -1, &in.d_buf, &in.d_size, 0, 0,
-				  memory_callback_arg);
+	      if (in_from_exec)
+		free (in.d_buf);
+	      else
+		(*memory_callback) (dwfl, -1, &in.d_buf, &in.d_size, 0, 0,
+				    memory_callback_arg);
 	      free (buf);
 	    }
 	  else
-- 
2.5.0