From bcdbeb844773333d2d1c08004f3b3e25921040e5 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 14 Dec 2016 14:55:56 -0500 Subject: [PATCH] USB: dummy-hcd: fix bug in stop_activity (handle ep0) The stop_activity() routine in dummy-hcd is supposed to unlink all active requests for every endpoint, among other things. But it doesn't handle ep0. As a result, fuzz testing can generate a WARNING like the following: WARNING: CPU: 0 PID: 4410 at drivers/usb/gadget/udc/dummy_hcd.c:672 dummy_free_request+0x153/0x170 Modules linked in: CPU: 0 PID: 4410 Comm: syz-executor Not tainted 4.9.0-rc7+ #32 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 ffff88006a64ed10 ffffffff81f96b8a ffffffff41b58ab3 1ffff1000d4c9d35 ffffed000d4c9d2d ffff880065f8ac00 0000000041b58ab3 ffffffff8598b510 ffffffff81f968f8 0000000041b58ab3 ffffffff859410e0 ffffffff813f0590 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [] dump_stack+0x292/0x398 lib/dump_stack.c:51 [] __warn+0x19f/0x1e0 kernel/panic.c:550 [] warn_slowpath_null+0x2c/0x40 kernel/panic.c:585 [] dummy_free_request+0x153/0x170 drivers/usb/gadget/udc/dummy_hcd.c:672 [] usb_ep_free_request+0xc0/0x420 drivers/usb/gadget/udc/core.c:195 [] gadgetfs_unbind+0x131/0x190 drivers/usb/gadget/legacy/inode.c:1612 [] usb_gadget_remove_driver+0x10f/0x2b0 drivers/usb/gadget/udc/core.c:1228 [] usb_gadget_unregister_driver+0x154/0x240 drivers/usb/gadget/udc/core.c:1357 This patch fixes the problem by iterating over all the endpoints in the driver's ep array instead of iterating over the gadget's ep_list, which explicitly leaves out ep0. Signed-off-by: Alan Stern Reported-by: Andrey Konovalov CC: Signed-off-by: Felipe Balbi --- drivers/usb/gadget/udc/dummy_hcd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c index 02b14e91ae6c..c60abe3a68f9 100644 --- a/drivers/usb/gadget/udc/dummy_hcd.c +++ b/drivers/usb/gadget/udc/dummy_hcd.c @@ -330,7 +330,7 @@ static void nuke(struct dummy *dum, struct dummy_ep *ep) /* caller must hold lock */ static void stop_activity(struct dummy *dum) { - struct dummy_ep *ep; + int i; /* prevent any more requests */ dum->address = 0; @@ -338,8 +338,8 @@ static void stop_activity(struct dummy *dum) /* The timer is left running so that outstanding URBs can fail */ /* nuke any pending requests first, so driver i/o is quiesced */ - list_for_each_entry(ep, &dum->gadget.ep_list, ep.ep_list) - nuke(dum, ep); + for (i = 0; i < DUMMY_ENDPOINTS; ++i) + nuke(dum, &dum->ep[i]); /* driver now does any non-usb quiescing necessary */ } -- 2.20.1