From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DD7B338655D; Sun, 13 Sep 2026 17:17:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789319851; cv=none; b=dlEKoqwjPc1qL/kCRvoeaOZduyE9gj+k99YLZ9ZgojUlaupVATz1Pqv+I4075iKhGzqMlDGF/2ZREQDt2NeVNhCuadWW6wbxPoPiEHbgigyR9TJdxgxFXzAPMx68S1Z6O5dPvJISfManRwE82/sKhBh0Tt6H6e5/CFp8E18guOA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789319851; c=relaxed/simple; bh=Hjb3jb3USV71UqUDGp095Qnz40Hf9kgKYHVuv3k5n7s=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=MLMwOjEZFpJdg5/KMCXeVxz+cckVAzNJsNPfWjuAVWs6KrMqlX1+xC1IF4p/U9XASNIwCGLd58wAOololuwdE+PnrPXe22tNwslsk+IbISDtxRVJ17GGu2jb+5gWJWIYZthBZ1k77kKGoWdzQHlHnPUaHz2C0/5jlNpkd1G6GDc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nL2fkYtQ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nL2fkYtQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3BFE1F00898; Sun, 13 Sep 2026 17:17:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789319843; bh=Raxewkw96Z82Y9nRPZmzJgCe1hQ47cf/cMMXBMB6o0o=; h=Date:From:To:Cc:Subject:References; b=nL2fkYtQ8ohLg8H5gnFrc29W83XppU0ipP2Riu+6c88MNitCroygteSukxj/cqAKr 94lMk263pDoVyHIfRW2O5VATDjVFjAq43EvYrihLWCrtddTcH3Gq7ttSIIgMYpGy/g ZSDCV/QK/m5zUU6UTpLx8YDHcDguRUc1g0+ldFs8eY5zS27IFzedrnXyQ2pMkSc5O9 8K1OLQ8wpmrlHWikZOjBKsIHxkNW72favqWKn5GQ5+7SbCt3qHm0s5KwXh76kJP+ce rm73oyPzU8xk/LSbM4TQPL6N/P++5D0qYwgYSz2R7V1mp5ObTI6EUiBed8KrFTUucN Olr/y2IsT3u2w== Received: from rostedt by gandalf with local (Exim 4.99.4) (envelope-from ) id 1x5nqr-0000000AQZc-3fRE; Sun, 13 Sep 2026 13:18:49 -0400 Message-ID: <20260913171849.676672435@kernel.org> User-Agent: quilt/0.69 Date: Sun, 13 Sep 2026 13:18:01 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , stable@vger.kernel.org, Alexander Gordeev , =?UTF-8?q?Ali=20Ahmet=20Memi=C5=9F?= Subject: [for-linus][PATCH 2/5] tracing: Dont dereference trace_event_file in deferred trigger free References: <20260913171759.469375546@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: =?UTF-8?q?Ali=20Ahmet=20Memi=C5=9F?= The enable_event trigger defers trace_event_put_ref() to the trigger free kthread, but the trace_event_file can already be freed when the instance is removed. Keep the trace_event_call directly in enable_trigger_data so the deferred free does not access the freed trace_event_file. Cc: stable@vger.kernel.org Fixes: e091351b3881 ("tracing: Delay module ref count for "enable_event" trigger") Reported-by: Alexander Gordeev Closes: https://lore.kernel.org/all/20260828134340.2501683A24-agordeev@linux.ibm.com/ Link: https://patch.msgid.link/20260911155650.354844-1-aliamemis@disroot.org Signed-off-by: Ali Ahmet Memiş Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 1 + kernel/trace/trace_events_trigger.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index bd3c8f80300f..3749485a7d85 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1953,6 +1953,7 @@ struct event_trigger_data { struct enable_trigger_data { struct trace_event_file *file; + struct trace_event_call *call; bool enable; bool hist; }; diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 149300cc5e8a..4d2fde996c0f 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -1728,7 +1728,8 @@ static void enable_trigger_private_data_free(struct event_trigger_data *data) { struct enable_trigger_data *enable_data = data->private_data; - trace_event_put_ref(enable_data->file->event_call); + /* The file may already be freed here, only the call is kept alive */ + trace_event_put_ref(enable_data->call); kfree(enable_data); } @@ -1801,6 +1802,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops, enable_data->hist = hist; enable_data->enable = enable; enable_data->file = event_enable_file; + enable_data->call = event_enable_file->event_call; trigger_data = trigger_data_alloc(cmd_ops, cmd, param, enable_data); if (!trigger_data) -- 2.53.0