[ 134/180] USB: CDC ACM: Fix NULL pointer dereference

[Willy Tarreau]

2.6.32-longterm review patch.  If anyone has any objections, please let me know.

------------------

From: Sven Schnelle <svens@xxxxxxxxxxxxxx>

commit 99f347caa4568cb803862730b3b1f1942639523f upstream.

If a device specifies zero endpoints in its interface descriptor,
the kernel oopses in acm_probe(). Even though that's clearly an
invalid descriptor, we should test wether we have all endpoints.
This is especially bad as this oops can be triggered by just
plugging a USB device in.

Signed-off-by: Sven Schnelle <svens@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Willy Tarreau <w@xxxxxx>
---
 drivers/usb/class/cdc-acm.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 653f853..8ad9dfb 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1120,7 +1120,8 @@ skip_normal_probe:
 	}
 
 
-	if (data_interface->cur_altsetting->desc.bNumEndpoints < 2)
+	if (data_interface->cur_altsetting->desc.bNumEndpoints < 2 ||
+	    control_interface->cur_altsetting->desc.bNumEndpoints == 0)
 		return -EINVAL;
 
 	epctrl = &control_interface->cur_altsetting->endpoint[0].desc;
-- 
1.7.2.1.45.g54fbc



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