From 2c25a2c818023df64463aac3288a9f969491e507 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 10 May 2017 18:18:27 +0200 Subject: USB: hub: fix SS hub-descriptor handling A SuperSpeed hub descriptor does not have any variable-length fields so bail out when reading a short descriptor. This avoids parsing and leaking two bytes of uninitialised slab data through sysfs removable-attributes. Fixes: dbe79bbe9dcb ("USB 3.0 Hub Changes") Cc: stable # 2.6.39 Cc: John Youn Acked-by: Alan Stern Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'drivers/usb/core/hub.c') diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 9dca59ef18b3..3ff1e9f89f2d 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -380,8 +380,12 @@ static int get_hub_descriptor(struct usb_device *hdev, void *data) USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB, dtype << 8, 0, data, size, USB_CTRL_GET_TIMEOUT); - if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2)) + if (hub_is_superspeed(hdev)) { + if (ret == size) + return ret; + } else if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2)) { return ret; + } } return -EINVAL; } @@ -1321,7 +1325,7 @@ static int hub_configure(struct usb_hub *hub, /* Request the entire hub descriptor. * hub->descriptor can handle USB_MAXCHILDREN ports, - * but the hub can/will return fewer bytes here. + * but a (non-SS) hub can/will return fewer bytes here. */ ret = get_hub_descriptor(hdev, hub->descriptor); if (ret < 0) { -- cgit v1.2.3 From bec444cd1c94c48df409a35ad4e5b143c245c3f7 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 10 May 2017 18:18:28 +0200 Subject: USB: hub: fix non-SS hub-descriptor handling Add missing sanity check on the non-SuperSpeed hub-descriptor length in order to avoid parsing and leaking two bytes of uninitialised slab data through sysfs removable-attributes (or a compound-device debug statement). Note that we only make sure that the DeviceRemovable field is always present (and specifically ignore the unused PortPwrCtrlMask field) in order to continue support any hubs with non-compliant descriptors. As a further safeguard, the descriptor buffer is also cleared. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable # 2.6.12 Signed-off-by: Johan Hovold Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'drivers/usb/core/hub.c') diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 3ff1e9f89f2d..f77a4ebde7d5 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -362,7 +362,8 @@ static void usb_set_lpm_parameters(struct usb_device *udev) } /* USB 2.0 spec Section 11.24.4.5 */ -static int get_hub_descriptor(struct usb_device *hdev, void *data) +static int get_hub_descriptor(struct usb_device *hdev, + struct usb_hub_descriptor *desc) { int i, ret, size; unsigned dtype; @@ -378,12 +379,16 @@ static int get_hub_descriptor(struct usb_device *hdev, void *data) for (i = 0; i < 3; i++) { ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0), USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB, - dtype << 8, 0, data, size, + dtype << 8, 0, desc, size, USB_CTRL_GET_TIMEOUT); if (hub_is_superspeed(hdev)) { if (ret == size) return ret; - } else if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2)) { + } else if (ret >= USB_DT_HUB_NONVAR_SIZE + 2) { + /* Make sure we have the DeviceRemovable field. */ + size = USB_DT_HUB_NONVAR_SIZE + desc->bNbrPorts / 8 + 1; + if (ret < size) + return -EMSGSIZE; return ret; } } @@ -1317,7 +1322,7 @@ static int hub_configure(struct usb_hub *hub, } mutex_init(&hub->status_mutex); - hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL); + hub->descriptor = kzalloc(sizeof(*hub->descriptor), GFP_KERNEL); if (!hub->descriptor) { ret = -ENOMEM; goto fail; -- cgit v1.2.3 From 93491ced3c87c94b12220dbac0527e1356702179 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 10 May 2017 18:18:29 +0200 Subject: USB: hub: fix SS max number of ports Add define for the maximum number of ports on a SuperSpeed hub as per USB 3.1 spec Table 10-5, and use it when verifying the retrieved hub descriptor. This specifically avoids benign attempts to update the DeviceRemovable mask for non-existing ports (should we get that far). Fixes: dbe79bbe9dcb ("USB 3.0 Hub Changes") Acked-by: Alan Stern Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 8 +++++++- include/uapi/linux/usb/ch11.h | 3 +++ 2 files changed, 10 insertions(+), 1 deletion(-) (limited to 'drivers/usb/core/hub.c') diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index f77a4ebde7d5..b8bb20d7acdb 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1336,7 +1336,13 @@ static int hub_configure(struct usb_hub *hub, if (ret < 0) { message = "can't read hub descriptor"; goto fail; - } else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) { + } + + maxchild = USB_MAXCHILDREN; + if (hub_is_superspeed(hdev)) + maxchild = min_t(unsigned, maxchild, USB_SS_MAXPORTS); + + if (hub->descriptor->bNbrPorts > maxchild) { message = "hub has too many ports!"; ret = -ENODEV; goto fail; diff --git a/include/uapi/linux/usb/ch11.h b/include/uapi/linux/usb/ch11.h index 361297e96f58..576c704e3fb8 100644 --- a/include/uapi/linux/usb/ch11.h +++ b/include/uapi/linux/usb/ch11.h @@ -22,6 +22,9 @@ */ #define USB_MAXCHILDREN 31 +/* See USB 3.1 spec Table 10-5 */ +#define USB_SS_MAXPORTS 15 + /* * Hub request types */ -- cgit v1.2.3