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| author | Johan Hovold <johan@kernel.org> | 2021-10-27 12:35:28 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-12 17:05:50 +0300 |
| commit | d6a727a681a39ae4f73081a9bedb45d14f95bdd1 (patch) | |
| tree | 4d14bfd1ddfaa27a12142398e4600aa863e3d2ea /drivers/comedi | |
| parent | 20cebb8b620dc987e55ddc46801de986e081757e (diff) | |
| download | linux-d6a727a681a39ae4f73081a9bedb45d14f95bdd1.tar.xz | |
comedi: ni_usb6501: fix NULL-deref in command paths
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>
Diffstat (limited to 'drivers/comedi')
| -rw-r--r-- | drivers/comedi/drivers/ni_usb6501.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/comedi/drivers/ni_usb6501.c b/drivers/comedi/drivers/ni_usb6501.c index 5b6d9d783b2f..c42987b74b1d 100644 --- a/drivers/comedi/drivers/ni_usb6501.c +++ b/drivers/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; } |