From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	sashiko-bot@kernel.org,
	Dmitry Torokhov <dmitry.torokhov@gmail.com>
Subject: [PATCH 6.18 046/217] Input: synaptics-rmi4 - propagate F54 worker errors to V4L2 queue
Date: Thu, 20 Aug 2026 16:53:34 +0200
Message-ID: <20260820145239.010466419@linuxfoundation.org>
In-Reply-To: <20260820145237.531699751@linuxfoundation.org>
References: <20260820145237.531699751@linuxfoundation.org>
User-Agent: quilt/0.69
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

commit 8786d74bf50e6797b6f655eb381ef6b25451161f upstream.

Previously, rmi_f54_buffer_queue() waited for the worker thread to
finish but ignored whether it succeeded. If the worker failed (e.g.,
due to a timeout or register read failure), the queue thread would
silently return success, delivering stale or uninitialized memory to
userspace.

Add a 'report_error' field to struct f54_data to store the worker's exit
status. Check this field in rmi_f54_buffer_queue() after the worker
finishes, and mark the buffer as VB2_BUF_STATE_ERROR if an error
occurred.

Fixes: 3a762dbd5347 ("[media] Input: synaptics-rmi4 - add support for F54 diagnostics")
Reported-by: sashiko-bot@kernel.org
Cc: stable@vger.kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Link: https://patch.msgid.link/20260626051802.4033172-6-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/input/rmi4/rmi_f54.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/input/rmi4/rmi_f54.c
+++ b/drivers/input/rmi4/rmi_f54.c
@@ -106,6 +106,7 @@ struct f54_data {
 	u8 *report_data;
 	size_t max_report_size;
 	int report_size;
+	int report_error;
 
 	bool is_busy;
 	struct mutex status_mutex;
@@ -340,6 +341,12 @@ static void rmi_f54_buffer_queue(struct
 		mutex_lock(&f54->data_mutex);
 	}
 
+	if (f54->report_error) {
+		dev_err(&f54->fn->dev, "Error acquiring report: %d\n", f54->report_error);
+		state = VB2_BUF_STATE_ERROR;
+		goto data_done;
+	}
+
 	ptr = vb2_plane_vaddr(vb, 0);
 	if (!ptr) {
 		dev_err(&f54->fn->dev, "Error acquiring frame ptr\n");
@@ -610,6 +617,7 @@ out:
 		report_size = 0;
 
 	f54->report_size = report_size;
+	f54->report_error = error;
 
 	if (report_size == 0 && !error) {
 		queue_delayed_work(f54->workqueue, &f54->work,