c409ca3be3
Change the validation of number_of_packets in get_pipe to compare the
number of packets to a fixed maximum number of packets allowed, set to
be 1024. This number was chosen due to it being used by other drivers as
well, for example drivers/usb/host/uhci-q.c
Background/reason:
The get_pipe function in stub_rx.c validates the number of packets in
isochronous mode and aborts with an error if that number is too large,
in order to prevent malicious input from possibly triggering large
memory allocations. This was previously done by checking whether
pdu->u.cmd_submit.number_of_packets is bigger than the number of packets
that would be needed for pdu->u.cmd_submit.transfer_buffer_length bytes
if all except possibly the last packet had maximum length, given by
usb_endpoint_maxp(epd) * usb_endpoint_maxp_mult(epd). This leads to an
error if URBs with packets shorter than the maximum possible length are
submitted, which is allowed according to
Documentation/driver-api/usb/URB.rst and occurs for example with the
snd-usb-audio driver.
Fixes: c6688ef9f297 ("usbip: fix stub_rx: harden CMD_SUBMIT path to handle malicious input")
Signed-off-by: Malte Leip <malte@leip.net>
Cc: stable <stable@vger.kernel.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.