From aa40560780b0cbea24d03b68570f3aac3b352da5 Mon Sep 17 00:00:00 2001
From: "Sven M. Hallberg" <pesco@khjk.org>
Date: Thu, 30 Mar 2023 13:40:42 +0000
Subject: [PATCH] report location of invalid startxref
This is useful information, especially in hex, when looking into the file.
The invalid value itself, on the other hand, is not so useful.
---
pdf.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/pdf.c b/pdf.c
index 97b2bb0..14e4a1d 100644
--- a/pdf.c
+++ b/pdf.c
@@ -4957,12 +4957,12 @@ parse_xrefs(const uint8_t *input, size_t sz, size_t *nxrefs)
HParseResult *res = NULL;
const HParsedToken **xrefs = NULL; /* empty result */
const HParsedToken *tok = NULL;
- size_t n = 0, nfwd = 0;
+ size_t i, n = 0, nfwd = 0;
size_t offset = 0;
/* search for the "startxref" section from the back of the file */
HParser *p = h_left(p_startxref, h_end_p()); // XXX alloc elsewhere?
- for (size_t i = 0; i < sz; i++) {
+ for (i = 0; i < sz; i++) {
res = h_parse(p, input + sz - i, i);
if (res != NULL)
break;
@@ -4979,8 +4979,8 @@ parse_xrefs(const uint8_t *input, size_t sz, size_t *nxrefs)
// verify the offset recovered is bounded to be in the file
// XXX this check is already present below by virtue of h_seek()
if (offset > sz) {
- log_message(5, "VIOLATION[5]: startxref %zu (%#zx) out of bounds\n",
- offset, offset);
+ log_message(5, "VIOLATION[5]: startxref at %zu (%#zx) points outside the file\n",
+ sz - i, sz - i);
goto end;
}
--
GitLab