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 9C4D947604A; Fri, 24 Jul 2026 23:18:31 +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=1784935113; cv=none; b=WdOoN8yyyVkqsswS7lFl+q4n3qGk41iqAwOon860QbmldJqyHhqPDsg1y0qh3bRCruPE5s+uOXQFgqMyDNUFNaTsbA0WyRL1AP8AnCoXnbPxPGlqv3E471chUUX4Dl+I7JxxP9Ay9s3hdbD/nV/GQQSvjaWwCePU1Jk+aCaJUjA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784935113; c=relaxed/simple; bh=Qll+//jgXXadWYprn+QPuI4SCLrd+jSg8/sUJmq5GuQ=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=jmmoR/HwF+Eq7k6dNKwC6RsiTu0CFz4WlbTE1aoP85dILmJJylkZ4UrqmjE3FN1P2Qd4m0UWypXzgDYBYDt7KrRVp9z4uInJo7Z+YKPRUu5nDWLrOuC/hnEDEyTEVVoTHEhE0bSJLCVxsXTGpdULNGYLGAgFAg0ZiDCkYNsp/1k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AX8SfgNG; 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="AX8SfgNG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2865D1F00ADF; Fri, 24 Jul 2026 23:18:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784935111; bh=OJWcsF5hPHMB0NRQDfte1CFKDsA//x9f6tzD+Q9jzVI=; h=Date:From:To:Cc:Subject:References; b=AX8SfgNG1rrAaMIETZANRwsr079nYaAPaJrbO5Ak6h3NETRENU/oD01qL2uCnvcvm Bi+u35zZMSbbe+2Am3z8ajqiq60N6FZaJWU2iQFtGYRwb5nCi656mmdEVhRuQ8QnnW OOo3qI81NNO5vpQLRLRoyjbjzxE46cEOmOXPp24Mgn0y7bOYL7U51EgNw4LBEbDf8r RD2aDuonIa+y0Q9cC+hYU+CrbCzDDMyVUsCfDnc6JkuAQsz/hi7rX98nEUPllycgJp RGn6zNQVUTLx0lWvDeKspc50LEZ3e4SXA0Zbig5wijPaBBQx4aSEJovqjKVoOjnf4l /WexXL9zMhXEg== Received: from rostedt by gandalf with local (Exim 4.99.4) (envelope-from ) id 1wnPAP-000000046vS-06K9; Fri, 24 Jul 2026 19:18:57 -0400 Message-ID: <20260724231856.879374418@kernel.org> User-Agent: quilt/0.69 Date: Fri, 24 Jul 2026 19:18:49 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , stable@vger.kernel.org, Sashiko Subject: [for-linus][PATCH 9/9] tracing: Delay module ref count for "enable_event" trigger References: <20260724231840.483353969@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: Steven Rostedt Triggers are now delayed from freeing, but can still be triggered until after the RCU grace period has ended. The freeing of the enable_event data is put into the private_data_free() callback, but the put of the module refcount is done immediately. It is possible that if a module is removed that has an event that would enable (or disable) it is still active, it can read the data of the module after it is removed causing a use-after-free bug. Move the trace_event_put_ref() that releases the module into the delayed callback so that the module can not be removed until any reference to its events are finished. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260724132415.1b5005db@gandalf.local.home Reported-by: Sashiko Link: https://sashiko.dev/#/patchset/20260724030523.19081-1-devnexen%40gmail.com Fixes: 61d445af0a7c ("tracing: Add bulk garbage collection of freeing event_trigger_data") Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_trigger.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 46e60b70a4bb..ad83419cb420 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -1726,7 +1726,10 @@ int event_enable_trigger_print(struct seq_file *m, static void enable_trigger_private_data_free(struct event_trigger_data *data) { - kfree(data->private_data); + struct enable_trigger_data *enable_data = data->private_data; + + trace_event_put_ref(enable_data->file->event_call); + kfree(enable_data); } void event_enable_trigger_free(struct event_trigger_data *data) @@ -1741,7 +1744,6 @@ void event_enable_trigger_free(struct event_trigger_data *data) /* Remove the SOFT_MODE flag */ trace_event_enable_disable(enable_data->file, 0, 1); data->private_data_free = enable_trigger_private_data_free; - trace_event_put_ref(enable_data->file->event_call); trigger_data_free(data); } } -- 2.53.0