diff options
| author | Lee Jones <lee@kernel.org> | 2026-10-19 12:07:29 +0000 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2026-10-19 10:47:46 -0400 |
| commit | 3403d9bb27ebc3572bd048620746b4414e073bf9 (patch) | |
| tree | 6e8c8eb02761547a921adaef85dc093a03a48b48 /kernel/trace/trace_events_synth.c | |
| parent | d5c42664fc094899af9aae5300b27fe8fdb658ef (diff) | |
tracing/histograms: Verify event_call identity when updating synth_event refcount
In event_hist_trigger_parse() and hist_unreg_all(), the histogram
registration and unregistration paths look up find_synth_event() using
trace_event_name(file->event_call) and adjust se->ref if a match is
found.
Because find_synth_event() only compares the event basename, registering
or removing a histogram on a non-synthetic trace event whose basename
matches a synthetic event erroneously modifies the synthetic event's
reference count. If a histogram is registered on the non-synthetic
event before the synthetic event is created and removed afterwards,
se->ref is decremented without a matching increment, allowing the
synthetic event to be freed while an active histogram action still holds
a pointer to it.
Introduce find_synth_event_call() to verify that &se->call matches
file->event_call before adjusting se->ref.
Fixes: 4b147936fa50 ("tracing: Add support for 'synthetic' events")
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20261019120730.2342739-1-lee@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_events_synth.c')
| -rw-r--r-- | kernel/trace/trace_events_synth.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index dc15658a887c..e2870212e58d 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -914,6 +914,16 @@ struct synth_event *find_synth_event(const char *name) return NULL; } +struct synth_event *find_synth_event_call(struct trace_event_call *call) +{ + struct synth_event *se; + const char *name; + + name = trace_event_name(call); + se = find_synth_event(name); + return se && &se->call == call ? se : NULL; +} + static struct trace_event_fields synth_event_fields_array[] = { { .type = TRACE_FUNCTION_TYPE, .define_fields = synth_event_define_fields }, |