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authorAlan Stern <stern@rowland.harvard.edu>2024-04-18 18:13:13 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-05-17 13:02:28 +0300
commit63533549ff53d24daf47c443dbd43c308afc3434 (patch)
treef449bbbdd40142efc853ca650bfc7b574ee3526b
parent7fce5501d7fc7051c9c99b6451e0dbd93856af4b (diff)
downloadlinux-63533549ff53d24daf47c443dbd43c308afc3434.tar.xz
USB: core: Fix access violation during port device removal
commit a4b46d450c49f32e9d4247b421e58083fde304ce upstream. Testing with KASAN and syzkaller revealed a bug in port.c:disable_store(): usb_hub_to_struct_hub() can return NULL if the hub that the port belongs to is concurrently removed, but the function does not check for this possibility before dereferencing the returned value. It turns out that the first dereference is unnecessary, since hub->intfdev is the parent of the port device, so it can be changed easily. Adding a check for hub == NULL prevents further problems. The same bug exists in the disable_show() routine, and it can be fixed the same way. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by: Yue Sun <samsun1006219@gmail.com> Reported-by: xingwei lee <xrivendell7@gmail.com> Link: https://lore.kernel.org/linux-usb/CAEkJfYON+ry7xPx=AiLR9jzUNT+i_Va68ACajOC3HoacOfL1ig@mail.gmail.com/ Fixes: f061f43d7418 ("usb: hub: port: add sysfs entry to switch port power") CC: Michael Grzeschik <m.grzeschik@pengutronix.de> CC: stable@vger.kernel.org Link: https://lore.kernel.org/r/393aa580-15a5-44ca-ad3b-6462461cd313@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/core/port.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index 76e00bfedc25..5fb3f55ef06d 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -50,13 +50,15 @@ static ssize_t disable_show(struct device *dev,
struct usb_port *port_dev = to_usb_port(dev);
struct usb_device *hdev = to_usb_device(dev->parent->parent);
struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
- struct usb_interface *intf = to_usb_interface(hub->intfdev);
+ struct usb_interface *intf = to_usb_interface(dev->parent);
int port1 = port_dev->portnum;
u16 portstatus, unused;
bool disabled;
int rc;
struct kernfs_node *kn;
+ if (!hub)
+ return -ENODEV;
hub_get(hub);
rc = usb_autopm_get_interface(intf);
if (rc < 0)
@@ -100,12 +102,14 @@ static ssize_t disable_store(struct device *dev, struct device_attribute *attr,
struct usb_port *port_dev = to_usb_port(dev);
struct usb_device *hdev = to_usb_device(dev->parent->parent);
struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
- struct usb_interface *intf = to_usb_interface(hub->intfdev);
+ struct usb_interface *intf = to_usb_interface(dev->parent);
int port1 = port_dev->portnum;
bool disabled;
int rc;
struct kernfs_node *kn;
+ if (!hub)
+ return -ENODEV;
rc = kstrtobool(buf, &disabled);
if (rc)
return rc;