From 93f8177d0ab219019180759949a882ecaf561225 Mon Sep 17 00:00:00 2001
From: David Linares <dlinares.linux@gmail.com>
Date: Mon, 25 Mar 2013 10:50:27 +0000
Subject: [PATCH] USB: hub: Avoid NULL pointer dereference when hub doesn't
have any ports
Return an error if hub->descriptor->bNbrPorts==0. Without this additional
check, we can end up doing a "hub->ports = kzalloc(0, GFP_KERNEL)".
This hub->ports pointer will therefore be non-NULL and will be used.
Example of dmesg:
INIT: usb 1-1: New USB device found, idVendor=0424, idProduct=2512
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
hub 1-1:1.0: USB hub found
version 2.86 bootinghub 1-1:1.0: 0 ports detected
Unable to handle kernel NULL pointer dereference at virtual address 00000010
Signed-off-by: David Linares <dlinares.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/core/hub.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 5480352f984dc..781546269d269 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1317,6 +1317,10 @@ static int hub_configure(struct usb_hub *hub,
message = "hub has too many ports!";
ret = -ENODEV;
goto fail;
+ } else if (hub->descriptor->bNbrPorts == 0) {
+ message = "hub doesn't have any ports!";
+ ret = -ENODEV;
+ goto fail;
}
hdev->maxchild = hub->descriptor->bNbrPorts;
--
2.39.5