[PATCH 4/4] tracing/eprobe: Fix exact system name matching in eprobe_dyn_event_match()

["Masami Hiramatsu (Google)" <mhiramat@kernel.org>]

From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

eprobe_dyn_event_match() checks if the target event system in argv[0]
matches ep->event_system using strncmp(ep->event_system, argv[0], len).
However, if ep->event_system is longer than len (e.g. "eprobes" vs
"ep/event"), strncmp() still returns 0 because the first len characters
match.

Check that ep->event_system[len] is '\0' to ensure exact system name
matching.

Fixes: 7d5fda1c841f ("tracing: Fix event probe removal from dynamic events")
Cc: stable@vger.kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 kernel/trace/trace_eprobe.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 50518b071414..bcd97cb24ac9 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -172,7 +172,8 @@ static bool eprobe_dyn_event_match(const char *system, const char *event,
 	if (!slash)
 		return false;
 
-	if (strncmp(ep->event_system, argv[0], slash - argv[0]))
+	if (strncmp(ep->event_system, argv[0], slash - argv[0]) ||
+	    ep->event_system[slash - argv[0]] != '\0')
 		return false;
 	if (strcmp(ep->event_name, slash + 1))
 		return false;