From f043bfc98c193c284e2cd768fefabe18ac2fed9b Mon Sep 17 00:00:00 2001 From: Jaejoong Kim Date: Thu, 28 Sep 2017 19:16:30 +0900 Subject: [PATCH] HID: usbhid: fix out-of-bounds bug The hid descriptor identifies the length and type of subordinate descriptors for a device. If the received hid descriptor is smaller than the size of the struct hid_descriptor, it is possible to cause out-of-bounds. In addition, if bNumDescriptors of the hid descriptor have an incorrect value, this can also cause out-of-bounds while approaching hdesc->desc[n]. So check the size of hid descriptor and bNumDescriptors. BUG: KASAN: slab-out-of-bounds in usbhid_parse+0x9b1/0xa20 Read of size 1 at addr ffff88006c5f8edf by task kworker/1:2/1261 CPU: 1 PID: 1261 Comm: kworker/1:2 Not tainted 4.14.0-rc1-42251-gebb2c2437d80 #169 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x292/0x395 lib/dump_stack.c:52 print_address_description+0x78/0x280 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 kasan_report+0x22f/0x340 mm/kasan/report.c:409 __asan_report_load1_noabort+0x19/0x20 mm/kasan/report.c:427 usbhid_parse+0x9b1/0xa20 drivers/hid/usbhid/hid-core.c:1004 hid_add_device+0x16b/0xb30 drivers/hid/hid-core.c:2944 usbhid_probe+0xc28/0x1100 drivers/hid/usbhid/hid-core.c:1369 usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932 generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174 usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 hub_port_connect drivers/usb/core/hub.c:4903 hub_port_connect_change drivers/usb/core/hub.c:5009 port_event drivers/usb/core/hub.c:5115 hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 worker_thread+0x221/0x1850 kernel/workqueue.c:2253 kthread+0x3a1/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Cc: stable@vger.kernel.org Reported-by: Andrey Konovalov Signed-off-by: Jaejoong Kim Tested-by: Andrey Konovalov Acked-by: Alan Stern Signed-off-by: Jiri Kosina --- drivers/hid/usbhid/hid-core.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c index 089bad8a9a21..045b5da9b992 100644 --- a/drivers/hid/usbhid/hid-core.c +++ b/drivers/hid/usbhid/hid-core.c @@ -975,6 +975,8 @@ static int usbhid_parse(struct hid_device *hid) unsigned int rsize = 0; char *rdesc; int ret, n; + int num_descriptors; + size_t offset = offsetof(struct hid_descriptor, desc); quirks = usbhid_lookup_quirk(le16_to_cpu(dev->descriptor.idVendor), le16_to_cpu(dev->descriptor.idProduct)); @@ -997,10 +999,18 @@ static int usbhid_parse(struct hid_device *hid) return -ENODEV; } + if (hdesc->bLength < sizeof(struct hid_descriptor)) { + dbg_hid("hid descriptor is too short\n"); + return -EINVAL; + } + hid->version = le16_to_cpu(hdesc->bcdHID); hid->country = hdesc->bCountryCode; - for (n = 0; n < hdesc->bNumDescriptors; n++) + num_descriptors = min_t(int, hdesc->bNumDescriptors, + (hdesc->bLength - offset) / sizeof(struct hid_class_descriptor)); + + for (n = 0; n < num_descriptors; n++) if (hdesc->desc[n].bDescriptorType == HID_DT_REPORT) rsize = le16_to_cpu(hdesc->desc[n].wDescriptorLength); -- 2.20.1