6.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dave Penkler dpenkler@gmail.com
[ Upstream commit 8491e73a5223acb0a4b4d78c3f8b96aa9c5e774d ]
If the agilent 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 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: fbae7090f30c ("staging: gpib: Update messaging and usb_device refs in agilent_usb") Cc: stable stable@kernel.org Signed-off-by: Dave Penkler dpenkler@gmail.com Link: https://lore.kernel.org/r/20250222204515.5104-1-dpenkler@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- .../gpib/agilent_82357a/agilent_82357a.c | 65 ++++++++++++++++--- 1 file changed, 55 insertions(+), 10 deletions(-)
diff --git a/drivers/staging/gpib/agilent_82357a/agilent_82357a.c b/drivers/staging/gpib/agilent_82357a/agilent_82357a.c index 7ebebe00dc489..e0d36f0dff25e 100644 --- a/drivers/staging/gpib/agilent_82357a/agilent_82357a.c +++ b/drivers/staging/gpib/agilent_82357a/agilent_82357a.c @@ -427,7 +427,7 @@ static int agilent_82357a_read(gpib_board_t *board, uint8_t *buffer, size_t leng { int retval; struct agilent_82357a_priv *a_priv = board->private_data; - struct usb_device *usb_dev = interface_to_usbdev(a_priv->bus_interface); + struct usb_device *usb_dev; u8 *out_data, *in_data; int out_data_length, in_data_length; int bytes_written, bytes_read; @@ -438,6 +438,10 @@ static int agilent_82357a_read(gpib_board_t *board, uint8_t *buffer, size_t leng
*nbytes = 0; *end = 0; + + if (!a_priv->bus_interface) + return -ENODEV; + usb_dev = interface_to_usbdev(a_priv->bus_interface); out_data_length = 0x9; out_data = kmalloc(out_data_length, GFP_KERNEL); if (!out_data) @@ -534,7 +538,7 @@ static ssize_t agilent_82357a_generic_write(gpib_board_t *board, uint8_t *buffer { int retval; struct agilent_82357a_priv *a_priv = board->private_data; - struct usb_device *usb_dev = interface_to_usbdev(a_priv->bus_interface); + struct usb_device *usb_dev; u8 *out_data = NULL; u8 *status_data = NULL; int out_data_length; @@ -545,6 +549,10 @@ static ssize_t agilent_82357a_generic_write(gpib_board_t *board, uint8_t *buffer struct agilent_82357a_register_pairlet read_reg;
*bytes_written = 0; + if (!a_priv->bus_interface) + return -ENODEV; + + usb_dev = interface_to_usbdev(a_priv->bus_interface); out_data_length = length + 0x8; out_data = kmalloc(out_data_length, GFP_KERNEL); if (!out_data) @@ -697,9 +705,13 @@ int agilent_82357a_take_control_internal(gpib_board_t *board, int synchronous)
static int agilent_82357a_take_control(gpib_board_t *board, int synchronous) { + struct agilent_82357a_priv *a_priv = board->private_data; const int timeout = 10; int i;
+ if (!a_priv->bus_interface) + return -ENODEV; + /* It looks like the 9914 does not handle tcs properly. * See comment above tms9914_take_control_workaround() in * drivers/gpib/tms9914/tms9914_aux.c @@ -723,10 +735,14 @@ static int agilent_82357a_take_control(gpib_board_t *board, int synchronous) static int agilent_82357a_go_to_standby(gpib_board_t *board) { struct agilent_82357a_priv *a_priv = board->private_data; - struct usb_device *usb_dev = interface_to_usbdev(a_priv->bus_interface); + struct usb_device *usb_dev; struct agilent_82357a_register_pairlet write; int retval;
+ if (!a_priv->bus_interface) + return -ENODEV; + + usb_dev = interface_to_usbdev(a_priv->bus_interface); write.address = AUXCR; write.value = AUX_GTS; retval = agilent_82357a_write_registers(a_priv, &write, 1); @@ -739,11 +755,15 @@ static int agilent_82357a_go_to_standby(gpib_board_t *board) static void agilent_82357a_request_system_control(gpib_board_t *board, int request_control) { struct agilent_82357a_priv *a_priv = board->private_data; - struct usb_device *usb_dev = interface_to_usbdev(a_priv->bus_interface); + struct usb_device *usb_dev; struct agilent_82357a_register_pairlet writes[2]; int retval; int i = 0;
+ if (!a_priv->bus_interface) + return; // -ENODEV; + + usb_dev = interface_to_usbdev(a_priv->bus_interface); /* 82357B needs bit to be set in 9914 AUXCR register */ writes[i].address = AUXCR; if (request_control) { @@ -767,10 +787,14 @@ static void agilent_82357a_request_system_control(gpib_board_t *board, int reque static void agilent_82357a_interface_clear(gpib_board_t *board, int assert) { struct agilent_82357a_priv *a_priv = board->private_data; - struct usb_device *usb_dev = interface_to_usbdev(a_priv->bus_interface); + struct usb_device *usb_dev; struct agilent_82357a_register_pairlet write; int retval;
+ if (!a_priv->bus_interface) + return; // -ENODEV; + + usb_dev = interface_to_usbdev(a_priv->bus_interface); write.address = AUXCR; write.value = AUX_SIC; if (assert) { @@ -785,10 +809,14 @@ static void agilent_82357a_interface_clear(gpib_board_t *board, int assert) static void agilent_82357a_remote_enable(gpib_board_t *board, int enable) { struct agilent_82357a_priv *a_priv = board->private_data; - struct usb_device *usb_dev = interface_to_usbdev(a_priv->bus_interface); + struct usb_device *usb_dev; struct agilent_82357a_register_pairlet write; int retval;
+ if (!a_priv->bus_interface) + return; //-ENODEV; + + usb_dev = interface_to_usbdev(a_priv->bus_interface); write.address = AUXCR; write.value = AUX_SRE; if (enable) @@ -804,6 +832,8 @@ static int agilent_82357a_enable_eos(gpib_board_t *board, uint8_t eos_byte, int { struct agilent_82357a_priv *a_priv = board->private_data;
+ if (!a_priv->bus_interface) + return -ENODEV; if (compare_8_bits == 0) return -EOPNOTSUPP;
@@ -822,10 +852,13 @@ static void agilent_82357a_disable_eos(gpib_board_t *board) static unsigned int agilent_82357a_update_status(gpib_board_t *board, unsigned int clear_mask) { struct agilent_82357a_priv *a_priv = board->private_data; - struct usb_device *usb_dev = interface_to_usbdev(a_priv->bus_interface); + struct usb_device *usb_dev; struct agilent_82357a_register_pairlet address_status, bus_status; int retval;
+ if (!a_priv->bus_interface) + return -ENODEV; + usb_dev = interface_to_usbdev(a_priv->bus_interface); board->status &= ~clear_mask; if (a_priv->is_cic) set_bit(CIC_NUM, &board->status); @@ -885,6 +918,9 @@ static int agilent_82357a_primary_address(gpib_board_t *board, unsigned int addr struct agilent_82357a_register_pairlet write; int retval;
+ if (!a_priv->bus_interface) + return -ENODEV; + usb_dev = interface_to_usbdev(a_priv->bus_interface); // put primary address in address0 write.address = ADR; write.value = address & ADDRESS_MASK; @@ -906,11 +942,14 @@ static int agilent_82357a_secondary_address(gpib_board_t *board, unsigned int ad static int agilent_82357a_parallel_poll(gpib_board_t *board, uint8_t *result) { struct agilent_82357a_priv *a_priv = board->private_data; - struct usb_device *usb_dev = interface_to_usbdev(a_priv->bus_interface); + struct usb_device *usb_dev; struct agilent_82357a_register_pairlet writes[2]; struct agilent_82357a_register_pairlet read; int retval;
+ if (!a_priv->bus_interface) + return -ENODEV; + usb_dev = interface_to_usbdev(a_priv->bus_interface); // execute parallel poll writes[0].address = AUXCR; writes[0].value = AUX_CS | AUX_RPP; @@ -975,11 +1014,14 @@ static void agilent_82357a_return_to_local(gpib_board_t *board) static int agilent_82357a_line_status(const gpib_board_t *board) { struct agilent_82357a_priv *a_priv = board->private_data; - struct usb_device *usb_dev = interface_to_usbdev(a_priv->bus_interface); + struct usb_device *usb_dev; struct agilent_82357a_register_pairlet bus_status; int retval; int status = ValidALL;
+ if (!a_priv->bus_interface) + return -ENODEV; + usb_dev = interface_to_usbdev(a_priv->bus_interface); bus_status.address = BSR; retval = agilent_82357a_read_registers(a_priv, &bus_status, 1, 0); if (retval) { @@ -1025,10 +1067,13 @@ static unsigned short nanosec_to_fast_talker_bits(unsigned int *nanosec) static unsigned int agilent_82357a_t1_delay(gpib_board_t *board, unsigned int nanosec) { struct agilent_82357a_priv *a_priv = board->private_data; - struct usb_device *usb_dev = interface_to_usbdev(a_priv->bus_interface); + struct usb_device *usb_dev; struct agilent_82357a_register_pairlet write; int retval;
+ if (!a_priv->bus_interface) + return -ENODEV; + usb_dev = interface_to_usbdev(a_priv->bus_interface); write.address = FAST_TALKER_T1; write.value = nanosec_to_fast_talker_bits(&nanosec); retval = agilent_82357a_write_registers(a_priv, &write, 1);