From: Johan Hovold <johan@kernel.org> stable inclusion from stable-v5.10.79 commit ef143dc0c3defe56730ecd3a9de7b3e1d7e557c1 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RD2V CVE: CVE-2021-47476 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 907767da8f3a925b060c740e0b5c92ea7dbec440 upstream. The driver uses endpoint-sized USB transfer buffers but had no sanity checks on the sizes. This can lead to zero-size-pointer dereferences or overflowed transfer buffers in ni6501_port_command() and ni6501_counter_command() if a (malicious) device has smaller max-packet sizes than expected (or when doing descriptor fuzz testing). Add the missing sanity checks to probe(). Fixes: a03bb00e50ab ("staging: comedi: add NI USB-6501 support") Cc: stable@vger.kernel.org # 3.18 Cc: Luca Ellero <luca.ellero@brickedbrain.com> Reviewed-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211027093529.30896-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Cui GaoSheng <cuigaosheng1@huawei.com> --- drivers/staging/comedi/drivers/ni_usb6501.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/staging/comedi/drivers/ni_usb6501.c b/drivers/staging/comedi/drivers/ni_usb6501.c index 1bb1cb651349..75e5b57ae0d7 100644 --- a/drivers/staging/comedi/drivers/ni_usb6501.c +++ b/drivers/staging/comedi/drivers/ni_usb6501.c @@ -144,6 +144,10 @@ static const u8 READ_COUNTER_RESPONSE[] = {0x00, 0x01, 0x00, 0x10, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00}; +/* Largest supported packets */ +static const size_t TX_MAX_SIZE = sizeof(SET_PORT_DIR_REQUEST); +static const size_t RX_MAX_SIZE = sizeof(READ_PORT_RESPONSE); + enum commands { READ_PORT, WRITE_PORT, @@ -501,6 +505,12 @@ static int ni6501_find_endpoints(struct comedi_device *dev) if (!devpriv->ep_rx || !devpriv->ep_tx) return -ENODEV; + if (usb_endpoint_maxp(devpriv->ep_rx) < RX_MAX_SIZE) + return -ENODEV; + + if (usb_endpoint_maxp(devpriv->ep_tx) < TX_MAX_SIZE) + return -ENODEV; + return 0; } -- 2.34.1