From: Kamal Agrawal kamaagra@codeaurora.org

The event_trace_add_tracer() can fail. In this case, it leads to a crash in start_creating with below call stack. Handle the error scenario properly in trace_array_create_dir.

Call trace: down_write+0x7c/0x204 start_creating.25017+0x6c/0x194 tracefs_create_file+0xc4/0x2b4 init_tracer_tracefs+0x5c/0x940 trace_array_create_dir+0x58/0xb4 trace_array_create+0x1bc/0x2b8 trace_array_get_by_name+0xdc/0x18c

Link: https://lkml.kernel.org/r/1627651386-21315-1-git-send-email-kamaagra@codeaur...

Cc: stable@vger.kernel.org Fixes: 4114fbfd02f1 ("tracing: Enable creating new instance early boot") Signed-off-by: Kamal Agrawal kamaagra@codeaurora.org Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org --- kernel/trace/trace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c59dd35a6da5..33899a71fdc1 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9135,8 +9135,10 @@ static int trace_array_create_dir(struct trace_array *tr) return -EINVAL;

ret = event_trace_add_tracer(tr->dir, tr); - if (ret) + if (ret) { tracefs_remove(tr->dir); + return ret; + }

init_tracer_tracefs(tr, tr->dir); __update_tracer_options(tr);