5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rahul Rameshbabu <sergeantsagara@xxxxxxxxxxxxxx> [ Upstream commit 4794394635293a3e74591351fff469cea7ad15a2 ] Reference the HID device rather than the input device for the devm allocation of the input_dev name. Referencing the input_dev would lead to a use-after-free when the input_dev was unregistered and subsequently fires a uevent that depends on the name. At the point of firing the uevent, the name would be freed by devres management. Use devm_kasprintf to simplify the logic for allocating memory and formatting the input_dev name string. Reported-by: Maxime Ripard <mripard@xxxxxxxxxx> Closes: https://lore.kernel.org/linux-input/ZOZIZCND+L0P1wJc@penguin/T/#m443f3dce92520f74b6cf6ffa8653f9c92643d4ae Fixes: c08d46aa805b ("HID: multitouch: devm conversion") Suggested-by: Maxime Ripard <mripard@xxxxxxxxxx> Suggested-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> Signed-off-by: Rahul Rameshbabu <sergeantsagara@xxxxxxxxxxxxxx> Reviewed-by: Maxime Ripard <mripard@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230824061308.222021-3-sergeantsagara@xxxxxxxxxxxxxx Signed-off-by: Benjamin Tissoires <bentiss@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/hid/hid-multitouch.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c index 9db327654580c..0893b31e6f102 100644 --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -1548,7 +1548,6 @@ static void mt_post_parse(struct mt_device *td, struct mt_application *app) static int mt_input_configured(struct hid_device *hdev, struct hid_input *hi) { struct mt_device *td = hid_get_drvdata(hdev); - char *name; const char *suffix = NULL; struct mt_report_data *rdata; struct mt_application *mt_application = NULL; @@ -1602,15 +1601,9 @@ static int mt_input_configured(struct hid_device *hdev, struct hid_input *hi) break; } - if (suffix) { - name = devm_kzalloc(&hi->input->dev, - strlen(hdev->name) + strlen(suffix) + 2, - GFP_KERNEL); - if (name) { - sprintf(name, "%s %s", hdev->name, suffix); - hi->input->name = name; - } - } + if (suffix) + hi->input->name = devm_kasprintf(&hdev->dev, GFP_KERNEL, + "%s %s", hdev->name, suffix); return 0; } -- 2.40.1
