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authorAlan Stern <stern@rowland.harvard.edu>2024-04-18 11:13:13 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-04-23 16:25:49 -0700
commita4b46d450c49f32e9d4247b421e58083fde304ce (patch)
tree1650d25d5b679fca20651fd0875f8987c2a1e193 /drivers/usb
parent6d735722063a945de56472bdc6bfcb170fd43b86 (diff)
USB: core: Fix access violation during port device removal
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>
Diffstat (limited to 'drivers/usb')
-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 0e1262a077ae..e7da2fca11a4 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -51,13 +51,15 @@ 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)
@@ -101,12 +103,14 @@ 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;