diff options
| author | Sebastian Rasmussen <sebras@gmail.com> | 2017-12-11 14:09:15 +0100 |
|---|---|---|
| committer | Sebastian Rasmussen <sebras@gmail.com> | 2017-12-13 21:38:26 +0100 |
| commit | 55c3f68d638ac1263a386e0aaa004bb6e8bde731 (patch) | |
| tree | 27fd12c9cea4acc2718674b47cda3c029c490e11 /source | |
| parent | c7a470081787cb85e6997dd611f24bfb280d55c2 (diff) | |
| download | mupdf-55c3f68d638ac1263a386e0aaa004bb6e8bde731.tar.xz | |
Bugs 698804/698810/698811: Keep PDF object numbers below limit.
This ensures that:
* xref tables with objects pointers do not grow out of bounds.
* other readers, e.g. Adobe Acrobat can parse PDFs written by mupdf.
Diffstat (limited to 'source')
| -rw-r--r-- | source/pdf/pdf-repair.c | 5 | ||||
| -rw-r--r-- | source/pdf/pdf-xref.c | 21 |
2 files changed, 13 insertions, 13 deletions
diff --git a/source/pdf/pdf-repair.c b/source/pdf/pdf-repair.c index ca149bd3..0c29758e 100644 --- a/source/pdf/pdf-repair.c +++ b/source/pdf/pdf-repair.c @@ -6,9 +6,6 @@ /* Scan file for objects and reconstruct xref table */ -/* Define in PDF 1.7 to be 8388607, but mupdf is more lenient. */ -#define MAX_OBJECT_NUMBER (10 << 20) - struct entry { int num; @@ -436,7 +433,7 @@ pdf_repair_xref(fz_context *ctx, pdf_document *doc) break; } - if (num <= 0 || num > MAX_OBJECT_NUMBER) + if (num <= 0 || num > PDF_MAX_OBJECT_NUMBER) { fz_warn(ctx, "ignoring object with invalid object number (%d %d R)", num, gen); goto have_next_token; diff --git a/source/pdf/pdf-xref.c b/source/pdf/pdf-xref.c index 00586dbd..6284e70b 100644 --- a/source/pdf/pdf-xref.c +++ b/source/pdf/pdf-xref.c @@ -868,11 +868,12 @@ pdf_read_old_xref(fz_context *ctx, pdf_document *doc, pdf_lexbuf *buf) fz_seek(ctx, file, -(2 + (int)strlen(s)), SEEK_CUR); } - if (ofs < 0) - fz_throw(ctx, FZ_ERROR_GENERIC, "out of range object num in xref: %d", (int)ofs); - if (ofs > INT64_MAX - len) - fz_throw(ctx, FZ_ERROR_GENERIC, "xref section object numbers too big"); - + if (ofs < 0 || ofs > PDF_MAX_OBJECT_NUMBER + || len < 0 || len > PDF_MAX_OBJECT_NUMBER + || ofs + len - 1 > PDF_MAX_OBJECT_NUMBER) + { + fz_throw(ctx, FZ_ERROR_GENERIC, "xref subsection object numbers are out of range"); + } /* broken pdfs where size in trailer undershoots entries in xref sections */ if (ofs + len > xref_len) { @@ -933,10 +934,8 @@ pdf_read_new_xref_section(fz_context *ctx, pdf_document *doc, fz_stream *stm, in pdf_xref_entry *table; int i, n; - if (i0 < 0 || i1 < 0 || i0 > INT_MAX - i1) - fz_throw(ctx, FZ_ERROR_GENERIC, "negative xref stream entry index"); - //if (i0 + i1 > pdf_xref_len(ctx, doc)) - // fz_throw(ctx, FZ_ERROR_GENERIC, "xref stream has too many entries"); + if (i0 < 0 || i0 > PDF_MAX_OBJECT_NUMBER || i1 < 0 || i1 > PDF_MAX_OBJECT_NUMBER || i0 + i1 - 1 > PDF_MAX_OBJECT_NUMBER) + fz_throw(ctx, FZ_ERROR_GENERIC, "xref subsection object numbers are out of range"); table = pdf_xref_find_subsection(ctx, doc, i0, i1); for (i = i0; i < i0 + i1; i++) @@ -2086,6 +2085,10 @@ pdf_create_object(fz_context *ctx, pdf_document *doc) /* TODO: reuse free object slots by properly linking free object chains in the ofs field */ pdf_xref_entry *entry; int num = pdf_xref_len(ctx, doc); + + if (num > PDF_MAX_OBJECT_NUMBER) + fz_throw(ctx, FZ_ERROR_GENERIC, "too many objects stored in pdf"); + entry = pdf_get_incremental_xref_entry(ctx, doc, num); entry->type = 'f'; entry->ofs = -1; |