diff options
Diffstat (limited to 'SOURCES/hid-wacom-correct-null-dereference-on-aes-pen-proximity.patch')
| -rw-r--r-- | SOURCES/hid-wacom-correct-null-dereference-on-aes-pen-proximity.patch | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/SOURCES/hid-wacom-correct-null-dereference-on-aes-pen-proximity.patch b/SOURCES/hid-wacom-correct-null-dereference-on-aes-pen-proximity.patch new file mode 100644 index 0000000..d76b648 --- /dev/null +++ b/SOURCES/hid-wacom-correct-null-dereference-on-aes-pen-proximity.patch @@ -0,0 +1,85 @@ +From MAILER-DAEMON Wed Jan 27 14:42:50 2021 +From: Jason Gerecke <killertofu@gmail.com> +To: linux-input@vger.kernel.org, Jiri Kosina <jikos@kernel.org>, Benjamin Tissoires <benjamin.tissoires@redhat.com> +Cc: Jason Gerecke <jason.gerecke@wacom.com>, stable@vger.kernel.org, Ping Cheng <ping.cheng@wacom.com> +Subject: [PATCH] HID: wacom: Correct NULL dereference on AES pen proximity +Date: Thu, 21 Jan 2021 10:46:49 -0800 +Message-Id: <20210121184649.157189-1-jason.gerecke@wacom.com> +List-ID: <linux-input.vger.kernel.org> +X-Mailing-List: linux-input@vger.kernel.org +MIME-Version: 1.0 +Content-Type: text/plain; charset="utf-8" +Content-Transfer-Encoding: 7bit + +The recent commit to fix a memory leak introduced an inadvertant NULL +pointer dereference. The `wacom_wac->pen_fifo` variable was never +intialized, resuling in a crash whenever functions tried to use it. +Since the FIFO is only used by AES pens (to buffer events from pen +proximity until the hardware reports the pen serial number) this would +have been easily overlooked without testing an AES device. + +This patch converts `wacom_wac->pen_fifo` over to a pointer (since the +call to `devres_alloc` allocates memory for us) and ensures that we assign +it to point to the allocated and initalized `pen_fifo` before the function +returns. + +Fixes: 37309f47e2f5 ("HID: wacom: Fix memory leakage caused by kfifo_alloc") +Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com> +Tested-by: Ping Cheng <ping.cheng@wacom.com> +CC: stable@vger.kernel.org # v4.19+ +Link: https://github.com/linuxwacom/input-wacom/issues/230 +--- + drivers/hid/wacom_sys.c | 7 ++++--- + drivers/hid/wacom_wac.h | 2 +- + 2 files changed, 5 insertions(+), 4 deletions(-) + +diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c +index e8acd235db2a..aa9e48876ced 100644 +--- a/drivers/hid/wacom_sys.c ++++ b/drivers/hid/wacom_sys.c +@@ -147,9 +147,9 @@ static int wacom_wac_pen_serial_enforce(struct hid_device *hdev, + } + + if (flush) +- wacom_wac_queue_flush(hdev, &wacom_wac->pen_fifo); ++ wacom_wac_queue_flush(hdev, wacom_wac->pen_fifo); + else if (insert) +- wacom_wac_queue_insert(hdev, &wacom_wac->pen_fifo, ++ wacom_wac_queue_insert(hdev, wacom_wac->pen_fifo, + raw_data, report_size); + + return insert && !flush; +@@ -1280,7 +1280,7 @@ static void wacom_devm_kfifo_release(struct device *dev, void *res) + static int wacom_devm_kfifo_alloc(struct wacom *wacom) + { + struct wacom_wac *wacom_wac = &wacom->wacom_wac; +- struct kfifo_rec_ptr_2 *pen_fifo = &wacom_wac->pen_fifo; ++ struct kfifo_rec_ptr_2 *pen_fifo; + int error; + + pen_fifo = devres_alloc(wacom_devm_kfifo_release, +@@ -1297,6 +1297,7 @@ static int wacom_devm_kfifo_alloc(struct wacom *wacom) + } + + devres_add(&wacom->hdev->dev, pen_fifo); ++ wacom_wac->pen_fifo = pen_fifo; + + return 0; + } +diff --git a/drivers/hid/wacom_wac.h b/drivers/hid/wacom_wac.h +index da612b6e9c77..195910dd2154 100644 +--- a/drivers/hid/wacom_wac.h ++++ b/drivers/hid/wacom_wac.h +@@ -342,7 +342,7 @@ struct wacom_wac { + struct input_dev *pen_input; + struct input_dev *touch_input; + struct input_dev *pad_input; +- struct kfifo_rec_ptr_2 pen_fifo; ++ struct kfifo_rec_ptr_2 *pen_fifo; + int pid; + int num_contacts_left; + u8 bt_features; +-- +2.30.0 + + |