diff options
| author | Steven Rostedt <rostedt@goodmis.org> | 2026-07-24 13:24:15 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2026-07-24 18:49:51 -0400 |
| commit | e091351b38818ef620d27f44f4bfd625f13afbff (patch) | |
| tree | 0855b12d43d2869674bc7ecbf08864998dcda7df | |
| parent | 79097812153b826fc156a2930ec8a90ed9edf4a2 (diff) | |
tracing: Delay module ref count for "enable_event" trigger
Triggers are now delayed from freeing, but can still be triggered until
after the RCU grace period has ended. The freeing of the enable_event data
is put into the private_data_free() callback, but the put of the module
refcount is done immediately.
It is possible that if a module is removed that has an event that would
enable (or disable) it is still active, it can read the data of the module
after it is removed causing a use-after-free bug.
Move the trace_event_put_ref() that releases the module into the delayed
callback so that the module can not be removed until any reference to its
events are finished.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260724132415.1b5005db@gandalf.local.home
Reported-by: Sashiko <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260724030523.19081-1-devnexen%40gmail.com
Fixes: 61d445af0a7c ("tracing: Add bulk garbage collection of freeing event_trigger_data")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/trace_events_trigger.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 46e60b70a4bb..ad83419cb420 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -1726,7 +1726,10 @@ int event_enable_trigger_print(struct seq_file *m, static void enable_trigger_private_data_free(struct event_trigger_data *data) { - kfree(data->private_data); + struct enable_trigger_data *enable_data = data->private_data; + + trace_event_put_ref(enable_data->file->event_call); + kfree(enable_data); } void event_enable_trigger_free(struct event_trigger_data *data) @@ -1741,7 +1744,6 @@ void event_enable_trigger_free(struct event_trigger_data *data) /* Remove the SOFT_MODE flag */ trace_event_enable_disable(enable_data->file, 0, 1); data->private_data_free = enable_trigger_private_data_free; - trace_event_put_ref(enable_data->file->event_call); trigger_data_free(data); } } |