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 587A94749F0; Fri, 7 Aug 2026 15:04:32 +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=1786115077; cv=none; b=PuXfol4rijz74bX3ChaOoYmi1G5mbSxDn+QuTsVUCVyutKGpv13Nqf7aZrn/mKhQg3UNrudrWAPfYt6tEWKHuYXn6GnptQBY4Zfve8luCJyQ+sRmcncxLq/UmPz0sDda0SZlL+jLKQA1hrFccItuMUM/6zsqMtpIFSzpksO/lUg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786115077; c=relaxed/simple; bh=1O/p+PHVrp8p4+aP7JMyGcwSPlishZPd931brLvyMgg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rNumsLPZFRFhqJgJd0PdbFYATOwu5gnoZps9ZUXKZZvhhWTCgh55fUDf4IW70CwO8cI3Y0ySVCoo49YoT//F5c8zDKgumnWmRJZrlcvFJ3Ueuh5JWlKyLOrUZMvpGmyRsYuhQh9qjimxui7JoY7mRj4Til1vK5gBr4kkOF+Lqzs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CHkrwrCy; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="CHkrwrCy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F8B61F00A3F; Fri, 7 Aug 2026 15:04:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786115070; bh=zx011pyxRaSq4qMGMGHtZzZz0NuU7Y8iGL2eA2gv+AU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=CHkrwrCy+zQr2hwxr1MrFQW4b0hbitPQ+PY70tdSRvnogQyNfEhPi9Y8VmzPthft0 Y3X+ECT+lrlV1OyjIdd7gR0UD8JNSD9eW1b0d712OA4D42rTGJl/yWUT2I+hLf1wD/ HL1kctctf5j6nwhpr4Ly3TA8pCCkWBlFL1v7/M34= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Masami Hiramatsu (Google)" , Steven Rostedt , Sasha Levin Subject: [PATCH 6.18 140/396] tracing/mmiotrace: Add NULL check for mmio_trace_array in logging functions Date: Fri, 7 Aug 2026 16:35:00 +0200 Message-ID: <20260807143427.330117927@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807143424.272339768@linuxfoundation.org> References: <20260807143424.272339768@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu (Google) [ Upstream commit 12b80cdbc54cf615b4717a4e8180063408091ea2 ] 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 Signed-off-by: Sasha Levin --- 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 e16b15d7c84aa..32b7e1d972a47 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