4.14-stable review patch. If anyone has any objections, please let me know.
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From: Rahul Rameshbabu sergeantsagara@protonmail.com
[ 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@kernel.org Closes: https://lore.kernel.org/linux-input/ZOZIZCND+L0P1wJc@penguin/T/#m443f3dce925... Fixes: c08d46aa805b ("HID: multitouch: devm conversion") Suggested-by: Maxime Ripard mripard@kernel.org Suggested-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Rahul Rameshbabu sergeantsagara@protonmail.com Reviewed-by: Maxime Ripard mripard@kernel.org Link: https://lore.kernel.org/r/20230824061308.222021-3-sergeantsagara@protonmail.... Signed-off-by: Benjamin Tissoires bentiss@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 0fa3bd2b035e7..55b1023af31fa 100644 --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -1136,7 +1136,6 @@ static void mt_post_parse(struct mt_device *td) 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 hid_field *field = hi->report->field[0]; int ret; @@ -1196,15 +1195,9 @@ static int mt_input_configured(struct hid_device *hdev, struct hid_input *hi) } }
- 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; }