[PATCH 4.5 072/101] tools lib traceevent: Do not reassign parg after collapse_tree()

[Greg Kroah-Hartman]

4.5-stable review patch.  If anyone has any objections, please let me know.

--

From: Steven Rostedt 

commit 106b816cb46ebd87408b4ed99a2e16203114daa6 upstream.

At the end of process_filter(), collapse_tree() was changed to update
the parg parameter, but the reassignment after the call wasn't removed.

What happens is that the "current_op" gets modified and freed and parg
is assigned to the new allocated argument. But after the call to
collapse_tree(), parg is assigned again to the just freed "current_op",
and this causes the tool to crash.

The current_op variable must also be assigned to NULL in case of error,
otherwise it will cause it to be free()ed twice.

Signed-off-by: Steven Rostedt 
Acked-by: Namhyung Kim 
Fixes: 42d6194d133c ("tools lib traceevent: Refactor process_filter()")
Link: http://lkml.kernel.org/r/20160511150936.678c1...@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman 

---
 tools/lib/traceevent/parse-filter.c |4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/tools/lib/traceevent/parse-filter.c
+++ b/tools/lib/traceevent/parse-filter.c
@@ -1164,11 +1164,11 @@ process_filter(struct event_format *even
current_op = current_exp;
 
ret = collapse_tree(current_op, parg, error_str);
+   /* collapse_tree() may free current_op, and updates parg accordingly */
+   current_op = NULL;
if (ret < 0)
goto fail;
 
-   *parg = current_op;
-
free(token);
return 0;
 

[PATCH 4.5 072/101] tools lib traceevent: Do not reassign parg after collapse_tree()

[Greg Kroah-Hartman]

4.5-stable review patch.  If anyone has any objections, please let me know.

--

From: Steven Rostedt 

commit 106b816cb46ebd87408b4ed99a2e16203114daa6 upstream.

At the end of process_filter(), collapse_tree() was changed to update
the parg parameter, but the reassignment after the call wasn't removed.

What happens is that the "current_op" gets modified and freed and parg
is assigned to the new allocated argument. But after the call to
collapse_tree(), parg is assigned again to the just freed "current_op",
and this causes the tool to crash.

The current_op variable must also be assigned to NULL in case of error,
otherwise it will cause it to be free()ed twice.

Signed-off-by: Steven Rostedt 
Acked-by: Namhyung Kim 
Fixes: 42d6194d133c ("tools lib traceevent: Refactor process_filter()")
Link: http://lkml.kernel.org/r/20160511150936.678c1...@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman 

---
 tools/lib/traceevent/parse-filter.c |4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/tools/lib/traceevent/parse-filter.c
+++ b/tools/lib/traceevent/parse-filter.c
@@ -1164,11 +1164,11 @@ process_filter(struct event_format *even
current_op = current_exp;
 
ret = collapse_tree(current_op, parg, error_str);
+   /* collapse_tree() may free current_op, and updates parg accordingly */
+   current_op = NULL;
if (ret < 0)
goto fail;
 
-   *parg = current_op;
-
free(token);
return 0;