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 242E43DE45C; Tue, 28 Jul 2026 12:50:07 +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=1785243012; cv=none; b=Xn5A8+I+GAgQIzvCP7ymHigR3I6x/5Z+6tQIxsHHQDLOsjqJL4MxewN3IK1Q60KVd/qMyle7xlLBsaSJBiAs8pxgKeR9p+qxqYbBXoClGZpTRh6Ni1Ml713FJuQR3glPQZjFTm2xE8HgGJi+at4qSkMVhn/lQgGGS5mlGs6bjTM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785243012; c=relaxed/simple; bh=7tFzBYGxtPyTEMNfVdoVrIcozUcGIBfaryyGKr/PGNY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=nhd1vZOvwdvsieFD6QvVmkjMfmrF6VC31/v4WKeM3lJ/2Zca5JeAD/N9xOGpbI7ybyeQrGXARijyT228q9LITqCfxKSwhDJzM0XunIg02qO8/+4J6KFxwCPxkM1dUu9laPAxeSbrIGIZA/q8YGxxPUMpR7NZAGEXwfKUZ60jpN4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gkr474Ek; 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="gkr474Ek" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EF7471F000E9; Tue, 28 Jul 2026 12:50:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785243004; bh=LaLFimEMmBrvMfMMx5gNeso5rpc7AUxMwn+69atIkjQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gkr474EkHDB2SsGE3JK1XRV2U+kQhMJ+j6uJKSXjjICdD5W19rNtzEwMhimnf9e0L bqFanGzGoGZZGLVA5HG/FObd/ne+erYbSJlR9DiA/8WQDHWlxkh9GBTW8YF8l4AZie 70Q8fYTJwsLkGDZrxBHtzCWOvAim6Q75QdLyfhyrr0IQ/CuBqIXdxTZj2aNKaGhw7w 4WcHYm/zaoHd9oeWxD9nwj8cAmEw+VKDcz43nRH59srqxktoXvrmVYgCtLbpd5CwPg OSq9IckLjMD8VdusbOYGB5mZwmBUPha8yj9nCBxwitaDHdDMVSXU+dJD/AD/MhUnVL +fNKNBYxi2COA== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Masami Hiramatsu Cc: Pekka Paalanen , Mathieu Desnoyers , linux-kernel@vger.kernel.org, nouveau@lists.freedesktop.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH 2/4] tracing/mmiotrace: Add NULL check for mmio_trace_array in logging functions Date: Tue, 28 Jul 2026 21:50:00 +0900 Message-ID: <178524300062.56416.8362487250709962380.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <178524298182.56416.7520852015178187644.stgit@devnote2> References: <178524298182.56416.7520852015178187644.stgit@devnote2> User-Agent: StGit/0.19 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" Content-Transfer-Encoding: 8bit From: Masami Hiramatsu (Google) mmio_trace_rw() and mmio_trace_mapping() retrieve mmio_trace_array into tr and pass it to __trace_mmiotrace_rw() and __trace_mmiotrace_map(). If these functions are invoked while mmio_trace_array is NULL (e.g. before initialization or after disabled), accessing tr->array_buffer.buffer will result in a NULL pointer dereference crash. Fix this by adding an explicit NULL check for tr at the beginning of __trace_mmiotrace_rw() and __trace_mmiotrace_map(). Fixes: f984b51e0779 ("ftrace: add mmiotrace plugin") Assisted-by: Antigravity:gemini-3.6-flash Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_mmiotrace.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index e064ba3f28cb..df8692c2dea8 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -294,11 +294,15 @@ device_initcall(init_mmio_trace); static void __trace_mmiotrace_rw(struct trace_array *tr, struct mmiotrace_rw *rw) { - struct trace_buffer *buffer = tr->array_buffer.buffer; + struct trace_buffer *buffer; struct ring_buffer_event *event; struct trace_mmiotrace_rw *entry; unsigned int trace_ctx; + if (!tr) + return; + + buffer = tr->array_buffer.buffer; trace_ctx = tracing_gen_ctx_flags(0); event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_RW, sizeof(*entry), trace_ctx); @@ -321,11 +325,15 @@ void mmio_trace_rw(struct mmiotrace_rw *rw) static void __trace_mmiotrace_map(struct trace_array *tr, struct mmiotrace_map *map) { - struct trace_buffer *buffer = tr->array_buffer.buffer; + struct trace_buffer *buffer; struct ring_buffer_event *event; struct trace_mmiotrace_map *entry; unsigned int trace_ctx; + if (!tr) + return; + + buffer = tr->array_buffer.buffer; trace_ctx = tracing_gen_ctx_flags(0); event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_MAP, sizeof(*entry), trace_ctx);