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| author | Oliver Neukum <oneukum@suse.com> | 2016-03-15 10:14:04 +0100 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-04-18 08:49:35 -0400 |
| commit | 4576d5d818abff73e363027f52da09519573c924 (patch) | |
| tree | f2bd7940d7d708c4b07cfede79792d2a3d747214 | |
| parent | 99790a913e5dbf8cf23f776aa546fc2feec767c7 (diff) | |
| download | lwn-4576d5d818abff73e363027f52da09519573c924.tar.gz lwn-4576d5d818abff73e363027f52da09519573c924.zip | |
USB: cdc-acm: more sanity checking
[ Upstream commit 8835ba4a39cf53f705417b3b3a94eb067673f2c9 ]
An attack has become available which pretends to be a quirky
device circumventing normal sanity checks and crashes the kernel
by an insufficient number of interfaces. This patch adds a check
to the code path for quirky devices.
Signed-off-by: Oliver Neukum <ONeukum@suse.com>
CC: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
| -rw-r--r-- | drivers/usb/class/cdc-acm.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 7ec2b06069c9..0dd514e86fdc 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1109,6 +1109,9 @@ static int acm_probe(struct usb_interface *intf, if (quirks == NO_UNION_NORMAL) { data_interface = usb_ifnum_to_if(usb_dev, 1); control_interface = usb_ifnum_to_if(usb_dev, 0); + /* we would crash */ + if (!data_interface || !control_interface) + return -ENODEV; goto skip_normal_probe; } |