5.4-stable review patch. If anyone has any objections, please let me know.
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From: Wolfram Sang wsa+renesas@sang-engineering.com
commit cbdb25ccf7566eee0c2b945e35cb98baf9ed0aa6 upstream.
This driver passes the length of an i2c_msg directly to usb_control_msg(). If the message is now a read and of length 0, it violates the USB protocol and a warning will be printed. Enable the I2C_AQ_NO_ZERO_LEN_READ quirk for this adapter thus forbidding 0-length read messages altogether.
Fixes: e8c76eed2ecd ("i2c: New i2c-tiny-usb bus driver") Signed-off-by: Wolfram Sang wsa+renesas@sang-engineering.com Cc: stable@vger.kernel.org # v2.6.22+ Signed-off-by: Andi Shyti andi.shyti@kernel.org Link: https://lore.kernel.org/r/20250522064349.3823-2-wsa+renesas@sang-engineering... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/i2c/busses/i2c-tiny-usb.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/drivers/i2c/busses/i2c-tiny-usb.c +++ b/drivers/i2c/busses/i2c-tiny-usb.c @@ -140,6 +140,11 @@ out: return ret; }
+/* prevent invalid 0-length usb_control_msg */ +static const struct i2c_adapter_quirks usb_quirks = { + .flags = I2C_AQ_NO_ZERO_LEN_READ, +}; + /* This is the actual algorithm we define */ static const struct i2c_algorithm usb_algorithm = { .master_xfer = usb_xfer, @@ -246,6 +251,7 @@ static int i2c_tiny_usb_probe(struct usb /* setup i2c adapter description */ dev->adapter.owner = THIS_MODULE; dev->adapter.class = I2C_CLASS_HWMON; + dev->adapter.quirks = &usb_quirks; dev->adapter.algo = &usb_algorithm; dev->adapter.algo_data = dev; snprintf(dev->adapter.name, sizeof(dev->adapter.name),