Commit 81f5c72d authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

USB: properly lock dynamic id list when showing an id 



When walking the list of dynamic ids for a driver, no lock was being
held, which meant that an id could be removed or added while the list
was being iterated.  Fix this up by properly grabing the lock while we
walk the list.

Reported-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Cc: linux-usb@vger.kernel.org
Link: https://lore.kernel.org/r/2024111324-tubby-facecloth-d4a0@gregkh


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0b3144da

drivers/usb/core/driver.c

+1 −0
Original line number Diff line number Diff line
@@ -116,6 +116,7 @@ ssize_t usb_show_dynids(struct usb_dynids *dynids, char *buf) 
	struct usb_dynid *dynid;

	size_t count = 0;



	guard(mutex)(&usb_dynids_lock);

	list_for_each_entry(dynid, &dynids->list, node)

		if (dynid->id.bInterfaceClass != 0)

			count += scnprintf(&buf[count], PAGE_SIZE - count, "%04x %04x %02x\n",