From 04887fa922365c77bf3502e49362f66144839caf Mon Sep 17 00:00:00 2001 From: John Thacker Date: Tue, 31 Mar 2026 11:19:57 +0000 Subject: [PATCH] USB HID: Skip items with a report size of zero Items with a report size of zero don't advance the offset and take up no room in the data, so there's nothing to display. It can lead to a very long loop if the report count is extremely long. Items with a non zero report size advance the offset, so we'll eventually throw an exception no matter the number of reported items. It's not clear from the USB HID spec if a report size of zero is legal, but it doesn't make much sense. Fix #21121 AI-Assisted: no (cherry picked from commit 9ed3457896839c66dd9459da6e7b893b0c94502f) Co-authored-by: John Thacker --- epan/dissectors/packet-usb-hid.c | 6 ++++++ 1 file changed, 6 insertions(+) Index: wireshark-3.6.24/epan/dissectors/packet-usb-hid.c =================================================================== --- wireshark-3.6.24.orig/epan/dissectors/packet-usb-hid.c +++ wireshark-3.6.24/epan/dissectors/packet-usb-hid.c @@ -5318,6 +5318,12 @@ dissect_usb_hid_data(tvbuff_t *tvb, pack if (rdesc->uses_report_id && field->report_id != report_id) continue; + /* skip items with a report size of 0 (no data and won't + * advance offset) */ + if (field->report_size == 0) { + continue; + } + /* if the item has no usages, it is padding - HID spec 6.2.2.9 */ if (wmem_array_get_count(field->usages) == 0) { proto_tree_add_bits_item(hid_tree, hf_usbhid_padding, tvb, hid_bit_offset, data_size, ENC_LITTLE_ENDIAN);