staging: gpib: Fix Oops after disconnect in ni_usb

If the usb dongle is disconnected subsequent calls to the
driver cause a NULL dereference Oops as the bus_interface
is set to NULL on disconnect.

This problem was introduced by setting usb_dev from the bus_interface
for dev_xxx messages.

Previously bus_interface was checked for NULL only in the the functions
directly calling usb_fill_bulk_urb or usb_control_msg.

Check for valid bus_interface on all interface entry points
and return -ENODEV if it is NULL.

Fixes: 4934b98bb243 ("staging: gpib: Update messaging and usb_device refs in ni_usb")
Cc: stable <stable@kernel.org>
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Link: https://lore.kernel.org/r/20250222165817.12856-1-dpenkler@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
index 61b15b19e13415cbcc9c76745a4afdd4237bc07a..62fbc78204ce5f0c757527545921b3d2e14efda2 100644 (file)
--- a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
+++ b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
@@ -591,7 +591,7 @@ static int ni_usb_read(gpib_board_t *board, uint8_t *buffer, size_t length,
 {
        int retval, parse_retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        u8 *out_data, *in_data;
        static const int out_data_length = 0x20;
        int in_data_length;
@@ -604,8 +604,11 @@ static int ni_usb_read(gpib_board_t *board, uint8_t *buffer, size_t length,
        struct ni_usb_register reg;
 
        *bytes_read = 0;
+       if (!ni_priv->bus_interface)
+               return -ENODEV;
        if (length > max_read_length)
                return -EINVAL;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        out_data = kmalloc(out_data_length, GFP_KERNEL);
        if (!out_data)
                return -ENOMEM;
@@ -718,7 +721,7 @@ static int ni_usb_write(gpib_board_t *board, uint8_t *buffer, size_t length,
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        u8 *out_data, *in_data;
        int out_data_length;
        static const int in_data_length = 0x10;
@@ -728,9 +731,11 @@ static int ni_usb_write(gpib_board_t *board, uint8_t *buffer, size_t length,
        struct ni_usb_status_block status;
        static const int max_write_length = 0xffff;
 
-       *bytes_written = 0;
+       if (!ni_priv->bus_interface)
+               return -ENODEV;
        if (length > max_write_length)
                return -EINVAL;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        out_data_length = length + 0x10;
        out_data = kmalloc(out_data_length, GFP_KERNEL);
        if (!out_data)
@@ -819,7 +824,7 @@ static int ni_usb_command_chunk(gpib_board_t *board, uint8_t *buffer, size_t len
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        u8 *out_data, *in_data;
        int out_data_length;
        static const int in_data_length = 0x10;
@@ -831,8 +836,11 @@ static int ni_usb_command_chunk(gpib_board_t *board, uint8_t *buffer, size_t len
        static const int max_command_length = 0x10;
 
        *command_bytes_written = 0;
+       if (!ni_priv->bus_interface)
+               return -ENODEV;
        if (length > max_command_length)
                length = max_command_length;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        out_data_length = length + 0x10;
        out_data = kmalloc(out_data_length, GFP_KERNEL);
        if (!out_data)
@@ -925,7 +933,7 @@ static int ni_usb_take_control(gpib_board_t *board, int synchronous)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        u8 *out_data, *in_data;
        static const int out_data_length = 0x10;
        static const int  in_data_length = 0x10;
@@ -933,6 +941,9 @@ static int ni_usb_take_control(gpib_board_t *board, int synchronous)
        int i = 0;
        struct ni_usb_status_block status;
 
+       if (!ni_priv->bus_interface)
+               return -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        out_data = kmalloc(out_data_length, GFP_KERNEL);
        if (!out_data)
                return -ENOMEM;
@@ -983,7 +994,7 @@ static int ni_usb_go_to_standby(gpib_board_t *board)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        u8 *out_data, *in_data;
        static const int out_data_length = 0x10;
        static const int  in_data_length = 0x20;
@@ -991,6 +1002,9 @@ static int ni_usb_go_to_standby(gpib_board_t *board)
        int i = 0;
        struct ni_usb_status_block status;
 
+       if (!ni_priv->bus_interface)
+               return -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        out_data = kmalloc(out_data_length, GFP_KERNEL);
        if (!out_data)
                return -ENOMEM;
@@ -1039,11 +1053,14 @@ static void ni_usb_request_system_control(gpib_board_t *board, int request_contr
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        int i = 0;
        struct ni_usb_register writes[4];
        unsigned int ibsta;
 
+       if (!ni_priv->bus_interface)
+               return; // -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        if (request_control) {
                writes[i].device = NIUSB_SUBDEV_TNT4882;
                writes[i].address = CMDR;
@@ -1087,7 +1104,7 @@ static void ni_usb_interface_clear(gpib_board_t *board, int assert)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        u8 *out_data, *in_data;
        static const int out_data_length = 0x10;
        static const int  in_data_length = 0x10;
@@ -1095,7 +1112,10 @@ static void ni_usb_interface_clear(gpib_board_t *board, int assert)
        int i = 0;
        struct ni_usb_status_block status;
 
-       // FIXME: we are going to pulse when assert is true, and ignore otherwise
+       if (!ni_priv->bus_interface)
+               return; // -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+// FIXME: we are going to pulse when assert is true, and ignore otherwise
        if (assert == 0)
                return;
        out_data = kmalloc(out_data_length, GFP_KERNEL);
@@ -1133,10 +1153,13 @@ static void ni_usb_remote_enable(gpib_board_t *board, int enable)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        struct ni_usb_register reg;
        unsigned int ibsta;
 
+       if (!ni_priv->bus_interface)
+               return; // -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        reg.device = NIUSB_SUBDEV_TNT4882;
        reg.address = nec7210_to_tnt4882_offset(AUXMR);
        if (enable)
@@ -1180,11 +1203,14 @@ static unsigned int ni_usb_update_status(gpib_board_t *board, unsigned int clear
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        static const int buffer_length = 8;
        u8 *buffer;
        struct ni_usb_status_block status;
 
+       if (!ni_priv->bus_interface)
+               return -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        buffer = kmalloc(buffer_length, GFP_KERNEL);
        if (!buffer)
                return board->status;
@@ -1232,11 +1258,14 @@ static int ni_usb_primary_address(gpib_board_t *board, unsigned int address)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        int i = 0;
        struct ni_usb_register writes[2];
        unsigned int ibsta;
 
+       if (!ni_priv->bus_interface)
+               return -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        writes[i].device = NIUSB_SUBDEV_TNT4882;
        writes[i].address = nec7210_to_tnt4882_offset(ADR);
        writes[i].value = address;
@@ -1287,11 +1316,14 @@ static int ni_usb_secondary_address(gpib_board_t *board, unsigned int address, i
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        int i = 0;
        struct ni_usb_register writes[3];
        unsigned int ibsta;
 
+       if (!ni_priv->bus_interface)
+               return -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        i += ni_usb_write_sad(writes, address, enable);
        retval = ni_usb_write_registers(ni_priv, writes, i, &ibsta);
        if (retval < 0) {
@@ -1306,7 +1338,7 @@ static int ni_usb_parallel_poll(gpib_board_t *board, uint8_t *result)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        u8 *out_data, *in_data;
        static const int out_data_length = 0x10;
        static const int  in_data_length = 0x20;
@@ -1315,6 +1347,9 @@ static int ni_usb_parallel_poll(gpib_board_t *board, uint8_t *result)
        int j = 0;
        struct ni_usb_status_block status;
 
+       if (!ni_priv->bus_interface)
+               return -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        out_data = kmalloc(out_data_length, GFP_KERNEL);
        if (!out_data)
                return -ENOMEM;
@@ -1358,11 +1393,14 @@ static void ni_usb_parallel_poll_configure(gpib_board_t *board, uint8_t config)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        int i = 0;
        struct ni_usb_register writes[1];
        unsigned int ibsta;
 
+       if (!ni_priv->bus_interface)
+               return; // -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        writes[i].device = NIUSB_SUBDEV_TNT4882;
        writes[i].address = nec7210_to_tnt4882_offset(AUXMR);
        writes[i].value = PPR | config;
@@ -1380,11 +1418,14 @@ static void ni_usb_parallel_poll_response(gpib_board_t *board, int ist)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        int i = 0;
        struct ni_usb_register writes[1];
        unsigned int ibsta;
 
+       if (!ni_priv->bus_interface)
+               return; // -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        writes[i].device = NIUSB_SUBDEV_TNT4882;
        writes[i].address = nec7210_to_tnt4882_offset(AUXMR);
        if (ist)
@@ -1405,11 +1446,14 @@ static void ni_usb_serial_poll_response(gpib_board_t *board, u8 status)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        int i = 0;
        struct ni_usb_register writes[1];
        unsigned int ibsta;
 
+       if (!ni_priv->bus_interface)
+               return; // -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        writes[i].device = NIUSB_SUBDEV_TNT4882;
        writes[i].address = nec7210_to_tnt4882_offset(SPMR);
        writes[i].value = status;
@@ -1432,11 +1476,14 @@ static void ni_usb_return_to_local(gpib_board_t *board)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        int i = 0;
        struct ni_usb_register writes[1];
        unsigned int ibsta;
 
+       if (!ni_priv->bus_interface)
+               return; // -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        writes[i].device = NIUSB_SUBDEV_TNT4882;
        writes[i].address = nec7210_to_tnt4882_offset(AUXMR);
        writes[i].value = AUX_RTL;
@@ -1454,7 +1501,7 @@ static int ni_usb_line_status(const gpib_board_t *board)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        u8 *out_data, *in_data;
        static const int out_data_length = 0x20;
        static const int  in_data_length = 0x20;
@@ -1464,6 +1511,9 @@ static int ni_usb_line_status(const gpib_board_t *board)
        int line_status = ValidALL;
        // NI windows driver reads 0xd(HSSEL), 0xc (ARD0), 0x1f (BSR)
 
+       if (!ni_priv->bus_interface)
+               return -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        out_data = kmalloc(out_data_length, GFP_KERNEL);
        if (!out_data)
                return -ENOMEM;
@@ -1570,12 +1620,15 @@ static unsigned int ni_usb_t1_delay(gpib_board_t *board, unsigned int nano_sec)
 {
        int retval;
        struct ni_usb_priv *ni_priv = board->private_data;
-       struct usb_device *usb_dev = interface_to_usbdev(ni_priv->bus_interface);
+       struct usb_device *usb_dev;
        struct ni_usb_register writes[3];
        unsigned int ibsta;
        unsigned int actual_ns;
        int i;
 
+       if (!ni_priv->bus_interface)
+               return -ENODEV;
+       usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        i = ni_usb_setup_t1_delay(writes, nano_sec, &actual_ns);
        retval = ni_usb_write_registers(ni_priv, writes, i, &ibsta);
        if (retval < 0) {