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 493303F4128; Wed, 29 Jul 2026 23:55:32 +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=1785369333; cv=none; b=S81rL+GQcPX93dUGdnjd/1jziwqr5eMszmhd6COhdt2tGX1DHWjAfHgsb3mEvO+TsSsFLWelRZ9FcCVFaTISK7VOyb19YirdRqeMMeCSCPkQB78hjf7H6flbhOCsGZeQk86rKkGrytJQbCVOgHWOLOuoWoiDGWHxCmi3qz49j7o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785369333; c=relaxed/simple; bh=1K/yFf8OfOB2rTNREVIOaRb3O5ohYzvmgE1OITnB8/s=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=G4OHcCFZFesX4tOkfR0uBBs2/zbm59/cMFsJDza7ZY0KV2M+p3coNCGNeOGHkZQGoKsfYkGZ2xWFWRMAyjdXkfhfebowT+LLi1urjKKOCtjKYImcpSwAC034jH6Qi9ZYuHJWaYHLQIt+pLTDqbquzlikX154cmdAEWwqwWEYgqo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Lc9M9dXy; 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="Lc9M9dXy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1AA741F00A3F; Wed, 29 Jul 2026 23:55:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785369332; bh=bO74R1ReXte6cxi92h8Rpsnbge6jM5VP3xm1gfelReg=; h=Date:From:To:Cc:Subject:References; b=Lc9M9dXyYq3uUcwzGybUB5aXMzN6PZ95pkf/1f6PEIcgD95DFztzd057aYocDYWhY RDD53AFRcNuKqDamdPeMcH/ULN4/onouPV21nC+0JKaJFsQz6HqCbevdXZOhd+5b+s E2/4+grHnJFKkZkK0vvcMrCbwEH9NWopwHt/1FFYLJZuz4gC6xpm/lfNYU0GKcHK1r 9mwcZY/EDPqTMwGahOVzPDPoMNnHX5Sv3gV/kDZSCQuuPNPJcgnpIJHmwdx1jMLyas TUaZUGhll0JEJjaphOUlunG8HdfRLXvJ6Svh3x4PAbNWbAYaGhAFmArqncbo/ApVOw PuNq3hHEseExg== Received: from rostedt by gandalf with local (Exim 4.99.4) (envelope-from ) id 1wpE88-00000007HZY-3YqV; Wed, 29 Jul 2026 19:56:08 -0400 Message-ID: <20260729235608.703242921@kernel.org> User-Agent: quilt/0.69 Date: Wed, 29 Jul 2026 19:55:54 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , stable@vger.kernel.org Subject: [for-linus][PATCH 3/5] tracing: Check return value of __register_event() in trace_module_add_events() References: <20260729235551.356165691@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 Link: https://patch.msgid.link/178528487878.124250.14170824576025743236.stgit@devnote2 Assisted-by: Antigravity:gemini-3.5-flash Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt --- 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); -- 2.53.0