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* [PATCH] tracing/probe: trace_probe_primary_from_call(): checked list_first_entry
@ 2023-01-28 16:23 Pietro Borrello
  2023-01-30 15:19 ` Steven Rostedt
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Pietro Borrello @ 2023-01-28 16:23 UTC (permalink / raw)
  To: Steven Rostedt, Masami Hiramatsu
  Cc: Cristiano Giuffrida, Bos, H.J.,
	Jakob Koschel, linux-kernel, linux-trace-kernel, Pietro Borrello

All callers of trace_probe_primary_from_call() check the return
value to be non NULL. However, the function returns
list_first_entry(&tpe->probes, ...) which can never be NULL.
Additionally, it does not check for the list being possibly empty,
possibly causing a type confusion on empty lists.
Use list_first_entry_or_null() which solves both problems.

Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
---
 kernel/trace/trace_probe.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 23acfd1c3812..f6b565dced56 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -307,7 +307,7 @@ trace_probe_primary_from_call(struct trace_event_call *call)
 {
 	struct trace_probe_event *tpe = trace_probe_event_from_call(call);
 
-	return list_first_entry(&tpe->probes, struct trace_probe, list);
+	return list_first_entry_or_null(&tpe->probes, struct trace_probe, list);
 }
 
 static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)

---
base-commit: 2241ab53cbb5cdb08a6b2d4688feb13971058f65
change-id: 20230128-list-entry-null-check-37778efda18c

Best regards,
-- 
Pietro Borrello <borrello@diag.uniroma1.it>

^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2023-02-17 13:44 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-01-28 16:23 [PATCH] tracing/probe: trace_probe_primary_from_call(): checked list_first_entry Pietro Borrello
2023-01-30 15:19 ` Steven Rostedt
2023-02-17  1:30 ` Masami Hiramatsu
2023-02-17 13:42 ` Mukesh Ojha

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