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authorTomas Bortoli <tomasbortoli@gmail.com>2019-05-28 17:43:38 +0200
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2019-05-28 16:27:58 -0400
commitdfb4a6f2191a80c8b790117d0ff592fd712d3296 (patch)
treeee5899455d1b43d2736e59c88e355ec4f1c08172
parent0c97bf863efce63d6ab7971dad811601e6171d2f (diff)
downloadlinux-dfb4a6f2191a80c8b790117d0ff592fd712d3296.tar.bz2
tracing: Avoid memory leak in predicate_parse()
In case of errors, predicate_parse() goes to the out_free label to free memory and to return an error code. However, predicate_parse() does not free the predicates of the temporary prog_stack array, thence leaking them. Link: http://lkml.kernel.org/r/20190528154338.29976-1-tomasbortoli@gmail.com Cc: stable@vger.kernel.org Fixes: 80765597bc587 ("tracing: Rewrite filter logic to be simpler and faster") Reported-by: syzbot+6b8e0fb820e570c59e19@syzkaller.appspotmail.com Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com> [ Added protection around freeing prog_stack[i].pred ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace_events_filter.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index d3e59312ef40..5079d1db3754 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -428,7 +428,7 @@ predicate_parse(const char *str, int nr_parens, int nr_preds,
op_stack = kmalloc_array(nr_parens, sizeof(*op_stack), GFP_KERNEL);
if (!op_stack)
return ERR_PTR(-ENOMEM);
- prog_stack = kmalloc_array(nr_preds, sizeof(*prog_stack), GFP_KERNEL);
+ prog_stack = kcalloc(nr_preds, sizeof(*prog_stack), GFP_KERNEL);
if (!prog_stack) {
parse_error(pe, -ENOMEM, 0);
goto out_free;
@@ -579,7 +579,11 @@ predicate_parse(const char *str, int nr_parens, int nr_preds,
out_free:
kfree(op_stack);
kfree(inverts);
- kfree(prog_stack);
+ if (prog_stack) {
+ for (i = 0; prog_stack[i].pred; i++)
+ kfree(prog_stack[i].pred);
+ kfree(prog_stack);
+ }
return ERR_PTR(ret);
}