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| author | Alan Stern <stern@rowland.harvard.edu> | 2021-05-26 17:32:44 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-27 13:46:21 +0200 |
| commit | 7652dd2c5cb7b656471cc801d619fe24120643a3 (patch) | |
| tree | 1df0b0a80088856a1f208a792c41558d7c4e611d /Documentation/driver-api/usb | |
| parent | usb: gadget: udc: udc-xilinx: Place correct function names into the headers (diff) | |
| download | linux-7652dd2c5cb7b656471cc801d619fe24120643a3.tar.xz linux-7652dd2c5cb7b656471cc801d619fe24120643a3.zip | |
USB: core: Check buffer length matches wLength for control transfers
A type of inconsistency that can show up in control URBs is when the
setup packet's wLength value does not match the URB's
transfer_buffer_length field. The two should always be equal;
differences could lead to information leaks or undefined behavior for
OUT transfers or overruns for IN transfers.
This patch adds a test for such mismatches during URB submission. If
the test fails, the submission is rejected with a -EBADR error code
(which is not used elsewhere in the USB core), and a debugging message
is logged for people interested in tracking down these errors.
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20210526153244.GA1400430@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/driver-api/usb')
| -rw-r--r-- | Documentation/driver-api/usb/error-codes.rst | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/driver-api/usb/error-codes.rst b/Documentation/driver-api/usb/error-codes.rst index a3e84bfac776..8f9790c2d6f8 100644 --- a/Documentation/driver-api/usb/error-codes.rst +++ b/Documentation/driver-api/usb/error-codes.rst @@ -61,6 +61,9 @@ USB-specific: (c) requested data transfer length is invalid: negative or too large for the host controller. +``-EBADR`` The wLength value in a control URB's setup packet does + not match the URB's transfer_buffer_length. + ``-ENOSPC`` This request would overcommit the usb bandwidth reserved for periodic transfers (interrupt, isochronous). |