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authorJohan Hovold <johan@kernel.org>2021-10-27 11:35:28 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-10-30 10:54:47 +0200
commit907767da8f3a925b060c740e0b5c92ea7dbec440 (patch)
tree8e0ea076a5c5d3899c1ece7f30aa2cba8a73fa7a /drivers/comedi
parent28eb3b363df76cb5fdffc5ef0498ca7dcedea4e7 (diff)
downloadlinux-907767da8f3a925b060c740e0b5c92ea7dbec440.tar.bz2
comedi: ni_usb6501: fix NULL-deref in command paths
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.c10
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;
}