From nobody Fri Sep 25 05:30:07 2026 Received: from cstnet.cn (smtp81.cstnet.cn [159.226.251.81]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A58B04A92EE; Wed, 16 Sep 2026 09:36:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.81 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789551369; cv=none; b=uyO5ScCE1Grm5cZOw12R7ahZ/1wMGocIhxgaHZ2XVYCfBIDXkDD0VDAVsRJhrL6tDb1GXOTo5pkEzOCUO/S7In4kcGkiVG0zPupW24lIg3Fm5WB+fhY0OBt/Qh+vRIDEoQy0wIHs7lODxUkS8oiryuQoChShMVTNtR/eM6JJhMc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789551369; c=relaxed/simple; bh=ueezB6h466N78udxdAAs3+YL41YsMPmJ91cXLkgiYls=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=NyORo7RNto3mvJEpiOkc/HbJwLIihiloaBPvz2UOJ2lxsd1zeOx7L87WJvO2l7Dn1xfhj6G5YIxRU2HMys35ylcQXW9eProCCJSetcFmdcqaT4PoXA/ReECKRO8d8hy8aXr7fGuohzMelSeEHMUwQl8hX67RAylTEE+6/wSUixs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.81 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from dfae2b116770.home.arpa (unknown [36.110.52.2]) by APP-03 (Coremail) with SMTP id rQCowACnqjj7YqpqpXTgBw--.42407S2; Wed, 16 Sep 2026 17:35:55 +0800 (CST) From: Wentao Liang To: arm-scmi@vger.kernel.org Cc: cristian.marussi@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, sudeep.holla@kernel.org, Wentao Liang , stable@vger.kernel.org Subject: [PATCH] firmware: arm_scmi: Fix msg use-after-free in virtio_mark_txdone() Date: Wed, 16 Sep 2026 09:35:27 +0000 Message-Id: <20260916093527.2004594-1-vulab@iscas.ac.cn> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: rQCowACnqjj7YqpqpXTgBw--.42407S2 X-Coremail-Antispam: 1UD129KBjvJXoW7KF18CrW5CF4kJr4DKFW5GFg_yoW8AFy5pF 4qga9xGw4UJF4xta48AF4kuFya9anYgr9xWry29aykCan8JF18XrWUAwn0gFyUArWxGa4j kF4ktrZrGF1DZrJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvj14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26ryj6F1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26F4j 6r4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oV Cq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUAVWUtwAv7VC2z280aVAFwI0_Gr1j6F4UJwAm72CE4IkC6x0Yz7v_Jr 0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxkF7I0En4kS14v2 6r126r1DMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrV AFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCI c40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1I6r4UMIIF0xvE2Ix0cI8IcVCY1x0267 AKxVWxJVW8Jr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r4j 6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73UjIFyTuYvjfUOM KuUUUUU X-CM-SenderInfo: pyxotu46lvutnvoduhdfq/1tbiCRQMA2qqP4eVTAAAsz Content-Type: text/plain; charset="utf-8" virtio_mark_txdone() can drop the last reference of a polled message while msg->poll_lock is still held, returning the message to the free-list where a concurrent sender can re-allocate it and race with the unlock at the end of the critical section. Hold a spare reference across the poll_lock critical section and drop it after the unlock. Fixes: 5a3b7185c47c ("firmware: arm_scmi: Add atomic mode support to virtio= transport") Cc: stable@vger.kernel.org Signed-off-by: Wentao Liang --- drivers/firmware/arm_scmi/transports/virtio.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/firmware/arm_scmi/transports/virtio.c b/drivers/firmwa= re/arm_scmi/transports/virtio.c index 326c4a93e44b..4bbd9dd2de83 100644 --- a/drivers/firmware/arm_scmi/transports/virtio.c +++ b/drivers/firmware/arm_scmi/transports/virtio.c @@ -616,6 +616,14 @@ static void virtio_mark_txdone(struct scmi_chan_info *= cinfo, int ret, return; } =20 + /* + * Hold a spare reference to msg so that it is not returned to the + * free-list while it is still accessed under poll_lock: a message + * sitting on the free-list can be re-allocated and re-initialized + * without taking poll_lock. + */ + scmi_vio_msg_acquire(msg); + spin_lock_irqsave(&msg->poll_lock, flags); /* Do not free timedout polled messages only if still inflight */ if (ret !=3D -ETIMEDOUT || msg->poll_status =3D=3D VIO_MSG_POLL_DONE) @@ -624,6 +632,8 @@ static void virtio_mark_txdone(struct scmi_chan_info *c= info, int ret, msg->poll_status =3D VIO_MSG_POLL_TIMEOUT; spin_unlock_irqrestore(&msg->poll_lock, flags); =20 + scmi_vio_msg_release(vioch, msg); + scmi_vio_channel_release(vioch); } =20 --=20 2.34.1