tracing: Consider the NULL character when validating the event length

[ Upstream commit 0b6e2e22cb23105fcb171ab92f0f7516c69c8471 ]

strlen() returns a string length excluding the null byte. If the string
length equals to the maximum buffer length, the buffer will have no
space for the NULL terminating character.

This commit checks this condition and returns failure for it.

Link: https://lore.kernel.org/all/20241007144724.920954-1-leo.yan@arm.com/
Fixes: dec65d79fd26 ("tracing/probe: Check event name length correctly")
Signed-off-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 39877c80d6cb9ace8163e2bfd16525629562ba82..16a5e368e7b77ca866895f271e33b6881e49cc4c 100644 (file)
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -276,7 +276,7 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
                }
                trace_probe_log_err(offset, NO_EVENT_NAME);
                return -EINVAL;
-       } else if (len > MAX_EVENT_NAME_LEN) {
+       } else if (len >= MAX_EVENT_NAME_LEN) {
                trace_probe_log_err(offset, EVENT_TOO_LONG);
                return -EINVAL;
        }