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 492943F12E0 for ; 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=YSjLHZ5q58Ay7C4S7HaLMzS5jvsE9cN/Dhs2LkvwKoKbxJsMGVIql7++VTtgY8BPbQLtutd4EtfAmuH5DhrSJUOoJE0WRE1krh0lgTrrykkV/APP2lkzqYhlRUriyZVkDgVSbHjYzwiX9FbauGYrz6T0mySytZaawMLH3fCdcNM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785369333; c=relaxed/simple; bh=CuxSifazLX3/hhuIH2GLlgnX3iej5nVolV+d3ePTG7c=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=I17FsW5f4QnDTtol/q7E3A47Px7/4UCU+6NOgCyY/fRO7xhgrr8H7BIZ5V/7h5VnzizunJ7uDpX+iwIL6U9jOmV2Ll2bcXNj0B8UzE6lHkYvxQYGvdFGAkGSdD7oNGCiacFsvnhDGgVYf5rqDL4zTNKosEN3eez0nPxB9RQEPz4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PXwXfSm+; 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="PXwXfSm+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAB3D1F00A3D; Wed, 29 Jul 2026 23:55:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785369332; bh=d6u5vb/q9STLH3yCtgoVDLE111W6E5wH5QqujKu0ysg=; h=Date:From:To:Cc:Subject:References; b=PXwXfSm+mXr+hirwtjwgCI7rSBRmIjRducZ6zyF9Sv/b1/l2vqpL6mW9fipVbIIgk X4ZKIr39JNao5T872b4UM3HV6FEeePB9zhjc9DtYzQJM5t3OlMGgiljgAetcnhWcEc 0vFgqhTMrX2zLjqRkF3OgAvBEURIy2kpeKsyfAUGPw/bk+GX5EtaBArFzewGv0R2yN YxkRCIf1xSa9vuVsdbTweqH9b9sDSev81eS4MsxrPyfM93AOYeQGizmdHWvvjkMCoy qsnWxLO4IOrEQDp8UWn0mcKkd+d82VfYtSrsZYwJtsVBferzdEBg5UA8tpIRLxlexv S5cw1aRfiSFtg== Received: from rostedt by gandalf with local (Exim 4.99.4) (envelope-from ) id 1wpE88-00000007HZ4-2sM7; Wed, 29 Jul 2026 19:56:08 -0400 Message-ID: <20260729235608.537291493@kernel.org> User-Agent: quilt/0.69 Date: Wed, 29 Jul 2026 19:55:53 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton Subject: [for-linus][PATCH 2/5] tracing/mmiotrace: Add NULL check for mmio_trace_array in logging functions References: <20260729235551.356165691@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: "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(). Link: https://patch.msgid.link/178524300062.56416.8362487250709962380.stgit@devnote2 Fixes: f984b51e0779 ("ftrace: add mmiotrace plugin") Assisted-by: Antigravity:gemini-3.6-flash Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt --- 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); -- 2.53.0