From cea357ad0501b8d4ab281716564833999308142f Mon Sep 17 00:00:00 2001 From: John Thacker Date: Fri, 3 Apr 2026 07:03:40 -0400 Subject: [PATCH] DCP ETSI: Check that all fragments are the same size with R-S ETSI TS 102.821 7.3.2 Fragmentation: "Note that when Reed Solomon has been used, all fragments will be of length s." Fix #21144 AI-Assisted: no (backported from 2a44f117ad799228bfe51467843b3a01fae3787c) --- epan/dissectors/packet-dcp-etsi.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) Index: wireshark-3.6.24/epan/dissectors/packet-dcp-etsi.c =================================================================== --- wireshark-3.6.24.orig/epan/dissectors/packet-dcp-etsi.c +++ wireshark-3.6.24/epan/dissectors/packet-dcp-etsi.c @@ -333,8 +333,15 @@ dissect_pft_fec_detailed(tvbuff_t * tvb, if(new_tvb && tvb_captured_length(new_tvb) > 0) { gboolean decoded; tvbuff_t *dtvb = NULL; - const guint8 *input = tvb_get_ptr(new_tvb, 0, -1); guint32 reassembled_size = tvb_captured_length(new_tvb); + /* "Note that when Reed Solomon has been used, all fragments will + * be of length s" [i.e., plen]" */ + if (reassembled_size != fcount * plen) { + proto_tree_add_expert_format(tree, pinfo, &ei_edcp_reassembly, new_tvb, 0, -1, "[All fragments must be the same size when Reed Solomon is used]"); + return NULL; + } + const guint8 *input = tvb_get_ptr(new_tvb, 0, reassembled_size); + guint8 *deinterleaved = (guint8*) wmem_alloc(pinfo->pool, reassembled_size); rs_deinterleave(input, deinterleaved, plen, fcount);