[PATCH 1/2] tools lib traceevent: Do not free tep->cmdlines in add_new_comm() on failure

From: Steven Rostedt
Date: Wed Aug 28 2019 - 15:18:27 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

If the re-allocation of tep->cmdlines succeeds, then the previous allocation
of tep->cmdlines will be freed. If we later fail in add_new_comm(), we must
not free cmdlines, and also should assign tep->cmdlines to the new
allocation. Otherwise when freeing tep, the tep->cmdlines will be pointing
to garbage.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: a6d2a61ac653a ("tools lib traceevent: Remove some die() calls")
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
tools/lib/traceevent/event-parse.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index b36b536a9fcb..13fd9fdf91e0 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -269,10 +269,10 @@ static int add_new_comm(struct tep_handle *tep,
errno = ENOMEM;
return -1;
}
+ tep->cmdlines = cmdlines;

cmdlines[tep->cmdline_count].comm = strdup(comm);
if (!cmdlines[tep->cmdline_count].comm) {
- free(cmdlines);
errno = ENOMEM;
return -1;
}
@@ -283,7 +283,6 @@ static int add_new_comm(struct tep_handle *tep,
tep->cmdline_count++;

qsort(cmdlines, tep->cmdline_count, sizeof(*cmdlines), cmdline_cmp);
- tep->cmdlines = cmdlines;

return 0;
}
--
2.20.1