diff options
| author | Steven Rostedt (Google) <rostedt@goodmis.org> | 2022-11-17 21:42:49 -0500 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2022-11-24 00:42:18 +0900 |
| commit | d5f30a7da8ea8e6450250275cec5670cee3c4264 (patch) | |
| tree | 97a735066d689fe1ffddf904bdbc002482223012 /kernel | |
| parent | 40adaf51cb318131073d1ba8233d473cc105ecbf (diff) | |
| download | linux-next-d5f30a7da8ea8e6450250275cec5670cee3c4264.tar.gz | |
tracing: Fix race where eprobes can be called before the event
The flag that tells the event to call its triggers after reading the event
is set for eprobes after the eprobe is enabled. This leads to a race where
the eprobe may be triggered at the beginning of the event where the record
information is NULL. The eprobe then dereferences the NULL record causing
a NULL kernel pointer bug.
Test for a NULL record to keep this from happening.
Link: https://lore.kernel.org/linux-trace-kernel/20221116192552.1066630-1-rafaelmendsr@gmail.com/
Link: https://lore.kernel.org/all/20221117214249.2addbe10@gandalf.local.home/
Cc: stable@vger.kernel.org
Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events")
Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_eprobe.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 123d2c0a6b68..352b65e2b910 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -564,6 +564,9 @@ static void eprobe_trigger_func(struct event_trigger_data *data, { struct eprobe_data *edata = data->private_data; + if (unlikely(!rec)) + return; + __eprobe_trace_func(edata, rec); } |