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 CD169231C91; Wed, 29 Jul 2026 00:28:02 +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=1785284884; cv=none; b=dUP7y4k6bVnPKKuauzj6pwJMrEgjQ/cf6sSmhNvS5YBFytNP3H3RumE5NzC73fuC8HJKKwVR1kLKTvuK0Ax00SgWi6RYVZxL3g69FaFwH+4NtN2WszFuU2AsDaJRCL5V97xueFrFvMnY1s5IWlTBHc/32XbgBx/VL7xrVg9IygM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785284884; c=relaxed/simple; bh=SJM/rbXXghSEhFRjdNCWGHyPQkb3lM0RJkb+mJSf/S0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CSP3XfxG9NxdOJZdCLgU9Yi0MYH1OSTCSN4k5einQHU6qSpn1sCgrxu6Iul2Uzaxl02AQywFm+At0IxhrXWoZvOt5xF998MNRyWmm6yxQdLmdEqz7gFX1iONXlKhbpFyzWGzK51nA+DjkBfYaCPKfF6K7yhM5slvdtFWl3o+5jA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a/+aikha; 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="a/+aikha" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 395351F000E9; Wed, 29 Jul 2026 00:28:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785284882; bh=tnjIRJfgkeEhkOivigyV6hxMYc+GhIm71QRqwZihsiA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=a/+aikhav81vhrKyCC9M7QNLJvidhbBcSckSJupfmAAW2N3ICwK9g9plptYKP357f TRjLocRrptGL/U3Y1j+hn4d66CKhEu+a6gv+9DnMW3K7LsPsF5ZVsZL1V4ehF0W/Lz moLoNiaLYZ2zGEO7CZd0DAtbzRuQ122MX6z6ZrtNY4N0NbCHaa2gwQiRUzqDRYT8S9 21u4+Vd7Sdr96/JYFCI6r/3wZkQv2cS0Vnd92Qw6eyS6feQP64gUS+on7mmmkmdzVl rf25d8WlzLV/oxFS7BJ+csqbHGmJHKRVz1Yc0q+DRvfdk+pb/T+M+7Ixsh0+KTTIFM lC+g8ToQKLnPA== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Masami Hiramatsu Cc: Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH 1/2] tracing: Check return value of __register_event() in trace_module_add_events() Date: Wed, 29 Jul 2026 09:27:58 +0900 Message-ID: <178528487878.124250.14170824576025743236.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <178528486942.124250.10437463913796837242.stgit@devnote2> References: <178528486942.124250.10437463913796837242.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit From: Masami Hiramatsu (Google) trace_module_add_events() ignores the return value of __register_event() and unconditionally calls __add_event_to_tracers() for each event. If __register_event() fails (for example, if event_init() fails), the trace_event_call is not added to ftrace_events list, but __add_event_to_tracers() still creates a trace_event_file pointing to it. If module loading subsequently fails and module memory is freed, tracing state retains a stale trace_event_call pointer in trace_event_file, leading to a use-after-free when tracefs or tracing subsystem operations are later executed. Fix this by checking the return value of __register_event() and only calling __add_event_to_tracers() if event registration succeeded. Fixes: ae63b31e4d0e ("tracing: Separate out trace events from global variables") Cc: stable@vger.kernel.org Assisted-by: Antigravity:gemini-3.5-flash Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_events.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 956692856fa8..c01b10b99f67 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -3933,8 +3933,8 @@ static void trace_module_add_events(struct module *mod) end = mod->trace_events + mod->num_trace_events; for_each_event(call, start, end) { - __register_event(*call, mod); - __add_event_to_tracers(*call); + if (!__register_event(*call, mod)) + __add_event_to_tracers(*call); } update_cache_events(mod);