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[188.141.5.72]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-c2966159c07sm441454566b.63.2026.09.14.06.35.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Sep 2026 06:35:08 -0700 (PDT) From: David Carlier To: rostedt@goodmis.org, mhiramat@kernel.org Cc: mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, David Carlier Subject: [PATCH v2 0/2] tracing: Fix buffer_meta open paths Date: Mon, 14 Sep 2026 14:35:03 +0100 Message-ID: <20260914133506.4865-1-devnexen@gmail.com> X-Mailer: git-send-email 2.55.0 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Two fixes for per_cpu/cpuN/buffer_meta open. The first drops the trace_array reference under trace_types_lock on the error path. The second fails the open for CPUs that never came online, which would otherwise dereference a NULL cpu_buffer on read. With the second patch, that error path becomes reachable in practice. Changes since v1: - Add patch 2 for the NULL dereference Sashiko reported on v1. v1: https://lore.kernel.org/all/20260913133829.15307-1-devnexen@gmail.com/ David Carlier (2): tracing: Take trace_types_lock when dropping the buffer_meta reference ring-buffer: Do not show buffer_meta for CPUs without a buffer kernel/trace/ring_buffer.c | 3 +++ kernel/trace/trace.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) -- 2.55.0