Hi Sergei,
On 1/9/2024 3:01 PM, Sergei Shtylyov wrote:
On 1/9/24 9:17 AM, Udipto Goswami wrote:
Currently,the function update_port_device_state gets the usb_hub from udev->parent by calling usb_hub_to_struct_hub. However, in case the actconfig or the maxchild is 0, the usb_hub would be NULL and upon further accessing to get port_dev would result in null pointer dereference.
Fix this by introducing an if check after the usb_hub is populated.
Fixes: 83cb2604f641 ("usb: core: add sysfs entry for usb device state") Cc: stable@vger.kernel.org Signed-off-by: Udipto Goswami quic_ugoswami@quicinc.com
v3: Re-wrote the comment for better context. v2: Introduced comment for the if check & CC'ed stable.
drivers/usb/core/hub.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index ffd7c99e24a3..6b514546e59b 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2053,9 +2053,23 @@ static void update_port_device_state(struct usb_device *udev) if (udev->parent) { hub = usb_hub_to_struct_hub(udev->parent);
port_dev = hub->ports[udev->portnum - 1];WRITE_ONCE(port_dev->state, udev->state);sysfs_notify_dirent(port_dev->state_kn);
/** The Link Layer Validation System Driver (lvstest)* has procedure of unbinding the hub before running* the rest of the procedure. This triggers* hub_disconnect will set the hub's maxchild to 0.I can't parse this sentence, s/th is missing...
Thanks for the review. Maybe this would sound better?
"This triggers hub_disconnect which will set hub's maxchild to 0"
* This would result usb_hub_to_struct_hub in this* function to return NULL."This would result in usb_hub_to_struct_hub in this functionreturning NULL", perhaps?
yah sound better. Will take care of it in next version.
Thanks, -Udipto