From 0a8fd1346254974c3a852338508e4a4cddbb35f1 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 19 Dec 2016 12:03:41 -0500 Subject: [PATCH] USB: fix problems with duplicate endpoint addresses When checking a new device's descriptors, the USB core does not check for duplicate endpoint addresses. This can cause a problem when the sysfs files for those endpoints are created; trying to create multiple files with the same name will provoke a WARNING: WARNING: CPU: 2 PID: 865 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x8a/0xa0 sysfs: cannot create duplicate filename '/devices/platform/dummy_hcd.0/usb2/2-1/2-1:64.0/ep_05' Kernel panic - not syncing: panic_on_warn set ... CPU: 2 PID: 865 Comm: kworker/2:1 Not tainted 4.9.0-rc7+ #34 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: usb_hub_wq hub_event ffff88006bee64c8 ffffffff81f96b8a ffffffff00000001 1ffff1000d7dcc2c ffffed000d7dcc24 0000000000000001 0000000041b58ab3 ffffffff8598b510 ffffffff81f968f8 ffffffff850fee20 ffffffff85cff020 dffffc0000000000 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [] dump_stack+0x292/0x398 lib/dump_stack.c:51 [] panic+0x1cb/0x3a9 kernel/panic.c:179 [] __warn+0x1c4/0x1e0 kernel/panic.c:542 [] warn_slowpath_fmt+0xc5/0x110 kernel/panic.c:565 [] sysfs_warn_dup+0x8a/0xa0 fs/sysfs/dir.c:30 [] sysfs_create_dir_ns+0x178/0x1d0 fs/sysfs/dir.c:59 [< inline >] create_dir lib/kobject.c:71 [] kobject_add_internal+0x227/0xa60 lib/kobject.c:229 [< inline >] kobject_add_varg lib/kobject.c:366 [] kobject_add+0x139/0x220 lib/kobject.c:411 [] device_add+0x353/0x1660 drivers/base/core.c:1088 [] device_register+0x1d/0x20 drivers/base/core.c:1206 [] usb_create_ep_devs+0x163/0x260 drivers/usb/core/endpoint.c:195 [] create_intf_ep_devs+0x13b/0x200 drivers/usb/core/message.c:1030 [] usb_set_configuration+0x1083/0x18d0 drivers/usb/core/message.c:1937 [] generic_probe+0x6e/0xe0 drivers/usb/core/generic.c:172 [] usb_probe_device+0xaa/0xe0 drivers/usb/core/driver.c:263 This patch prevents the problem by checking for duplicate endpoint addresses during enumeration and skipping any duplicates. Signed-off-by: Alan Stern Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov CC: Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/config.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 0aa9e7d697a5..25dbd8c7aec7 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -239,6 +239,16 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, if (ifp->desc.bNumEndpoints >= num_ep) goto skip_to_next_endpoint_or_interface_descriptor; + /* Check for duplicate endpoint addresses */ + for (i = 0; i < ifp->desc.bNumEndpoints; ++i) { + if (ifp->endpoint[i].desc.bEndpointAddress == + d->bEndpointAddress) { + dev_warn(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n", + cfgno, inum, asnum, d->bEndpointAddress); + goto skip_to_next_endpoint_or_interface_descriptor; + } + } + endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints]; ++ifp->desc.bNumEndpoints;