From f0343565edd3679210c598d3361ad9530829e73c Mon Sep 17 00:00:00 2001 From: m-holger Date: Wed, 17 Jan 2024 14:07:37 +0000 Subject: [PATCH] Tighten checks for invalid indirect references during xref reconstruction --- libqpdf/QPDF.cc | 4 ++++ qpdf/qpdf.testcov | 1 + qpdf/qtest/qpdf/obj0-check.out | 1 - 3 files changed, 5 insertions(+), 1 deletion(-) diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc index 8cff3dfd..01158ce2 100644 --- a/libqpdf/QPDF.cc +++ b/libqpdf/QPDF.cc @@ -1195,6 +1195,10 @@ QPDF::insertFreeXrefEntry(QPDFObjGen og) void QPDF::insertReconstructedXrefEntry(int obj, qpdf_offset_t f1, int f2) { + if (!(obj > 0 && 0 <= f2 && f2 < 65535)) { + QTC::TC("qpdf", "QPDF xref overwrite invalid objgen"); + return; + } QPDFObjGen og(obj, f2); if (!m->deleted_objects.count(obj)) { // deleted_objects stores the uncompressed objects removed from the xref table at the start diff --git a/qpdf/qpdf.testcov b/qpdf/qpdf.testcov index e7b6a8a2..51c3ea72 100644 --- a/qpdf/qpdf.testcov +++ b/qpdf/qpdf.testcov @@ -105,6 +105,7 @@ QPDF_encryption xref stream from encrypted file 0 QPDFJob unable to filter 0 QUtil non-trivial UTF-16 0 QPDF xref overwrite object 0 +QPDF xref overwrite invalid objgen 0 QPDF decoding error warning 0 qpdf-c called qpdf_init 0 qpdf-c called qpdf_cleanup 0 diff --git a/qpdf/qtest/qpdf/obj0-check.out b/qpdf/qtest/qpdf/obj0-check.out index 7a17e8a7..785131d4 100644 --- a/qpdf/qtest/qpdf/obj0-check.out +++ b/qpdf/qtest/qpdf/obj0-check.out @@ -5,5 +5,4 @@ checking obj0.pdf PDF Version: 1.3 File is not encrypted File is not linearized -WARNING: obj0.pdf (offset 15): object with ID 0 qpdf: operation succeeded with warnings