From: Terry Junge <linuxhid@cosmicgizmosystems.com> stable inclusion from stable-v6.6.94 commit 4fa7831cf0ac71a0a345369d1a6084f2b096e55e category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICJT9G CVE: CVE-2025-38103 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit fe7f7ac8e0c708446ff017453add769ffc15deed upstream. Update struct hid_descriptor to better reflect the mandatory and optional parts of the HID Descriptor as per USB HID 1.11 specification. Note: the kernel currently does not parse any optional HID class descriptors, only the mandatory report descriptor. Update all references to member element desc[0] to rpt_desc. Add test to verify bLength and bNumDescriptors values are valid. Replace the for loop with direct access to the mandatory HID class descriptor member for the report descriptor. This eliminates the possibility of getting an out-of-bounds fault. Add a warning message if the HID descriptor contains any unsupported optional HID class descriptors. Reported-by: syzbot+c52569baf0c843f35495@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c52569baf0c843f35495 Fixes: f043bfc98c19 ("HID: usbhid: fix out-of-bounds bug") Cc: stable@vger.kernel.org Signed-off-by: Terry Junge <linuxhid@cosmicgizmosystems.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Jiri Kosina <jkosina@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Wang Tao <wangtao554@huawei.com> --- drivers/hid/hid-hyperv.c | 4 ++-- drivers/hid/usbhid/hid-core.c | 25 ++++++++++++++----------- drivers/usb/gadget/function/f_hid.c | 12 ++++++------ include/linux/hid.h | 3 ++- 4 files changed, 24 insertions(+), 20 deletions(-) diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c index 0fb210e40a41..9eafff0b6ea4 100644 --- a/drivers/hid/hid-hyperv.c +++ b/drivers/hid/hid-hyperv.c @@ -192,7 +192,7 @@ static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device, goto cleanup; input_device->report_desc_size = le16_to_cpu( - desc->desc[0].wDescriptorLength); + desc->rpt_desc.wDescriptorLength); if (input_device->report_desc_size == 0) { input_device->dev_info_status = -EINVAL; goto cleanup; @@ -210,7 +210,7 @@ static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device, memcpy(input_device->report_desc, ((unsigned char *)desc) + desc->bLength, - le16_to_cpu(desc->desc[0].wDescriptorLength)); + le16_to_cpu(desc->rpt_desc.wDescriptorLength)); /* Send the ack */ memset(&ack, 0, sizeof(struct mousevsc_prt_msg)); diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c index 257dd73e37bf..a8e8da002b9b 100644 --- a/drivers/hid/usbhid/hid-core.c +++ b/drivers/hid/usbhid/hid-core.c @@ -982,12 +982,11 @@ static int usbhid_parse(struct hid_device *hid) struct usb_host_interface *interface = intf->cur_altsetting; struct usb_device *dev = interface_to_usbdev (intf); struct hid_descriptor *hdesc; + struct hid_class_descriptor *hcdesc; u32 quirks = 0; unsigned int rsize = 0; char *rdesc; - int ret, n; - int num_descriptors; - size_t offset = offsetof(struct hid_descriptor, desc); + int ret; quirks = hid_lookup_quirk(hid); @@ -1009,20 +1008,19 @@ 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"); + if (!hdesc->bNumDescriptors || + hdesc->bLength != sizeof(*hdesc) + + (hdesc->bNumDescriptors - 1) * sizeof(*hcdesc)) { + dbg_hid("hid descriptor invalid, bLen=%hhu bNum=%hhu\n", + hdesc->bLength, hdesc->bNumDescriptors); return -EINVAL; } hid->version = le16_to_cpu(hdesc->bcdHID); hid->country = hdesc->bCountryCode; - 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); + if (hdesc->rpt_desc.bDescriptorType == HID_DT_REPORT) + rsize = le16_to_cpu(hdesc->rpt_desc.wDescriptorLength); if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { dbg_hid("weird size of report descriptor (%u)\n", rsize); @@ -1050,6 +1048,11 @@ static int usbhid_parse(struct hid_device *hid) goto err; } + if (hdesc->bNumDescriptors > 1) + hid_warn(intf, + "%u unsupported optional hid class descriptors\n", + (int)(hdesc->bNumDescriptors - 1)); + hid->quirks |= quirks; return 0; diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c index 2db01e03bfbf..2f1ec03d17d6 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -118,8 +118,8 @@ static struct hid_descriptor hidg_desc = { .bcdHID = cpu_to_le16(0x0101), .bCountryCode = 0x00, .bNumDescriptors = 0x1, - /*.desc[0].bDescriptorType = DYNAMIC */ - /*.desc[0].wDescriptorLenght = DYNAMIC */ + /*.rpt_desc.bDescriptorType = DYNAMIC */ + /*.rpt_desc.wDescriptorLength = DYNAMIC */ }; /* Super-Speed Support */ @@ -728,8 +728,8 @@ static int hidg_setup(struct usb_function *f, struct hid_descriptor hidg_desc_copy = hidg_desc; VDBG(cdev, "USB_REQ_GET_DESCRIPTOR: HID\n"); - hidg_desc_copy.desc[0].bDescriptorType = HID_DT_REPORT; - hidg_desc_copy.desc[0].wDescriptorLength = + hidg_desc_copy.rpt_desc.bDescriptorType = HID_DT_REPORT; + hidg_desc_copy.rpt_desc.wDescriptorLength = cpu_to_le16(hidg->report_desc_length); length = min_t(unsigned short, length, @@ -970,8 +970,8 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f) * We can use hidg_desc struct here but we should not relay * that its content won't change after returning from this function. */ - hidg_desc.desc[0].bDescriptorType = HID_DT_REPORT; - hidg_desc.desc[0].wDescriptorLength = + hidg_desc.rpt_desc.bDescriptorType = HID_DT_REPORT; + hidg_desc.rpt_desc.wDescriptorLength = cpu_to_le16(hidg->report_desc_length); hidg_hs_in_ep_desc.bEndpointAddress = diff --git a/include/linux/hid.h b/include/linux/hid.h index 774cb25dec34..22ece7a07569 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -736,8 +736,9 @@ struct hid_descriptor { __le16 bcdHID; __u8 bCountryCode; __u8 bNumDescriptors; + struct hid_class_descriptor rpt_desc; - struct hid_class_descriptor desc[1]; + struct hid_class_descriptor opt_descs[]; } __attribute__ ((packed)); #define HID_DEVICE(b, g, ven, prod) \ -- 2.34.1