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| author | Robin Watts <robin.watts@artifex.com> | 2012-11-29 18:53:58 +0000 |
|---|---|---|
| committer | Robin Watts <robin.watts@artifex.com> | 2012-11-30 13:26:03 +0000 |
| commit | 980e2932579e3ede636297b49baf12ad1bc8b2a7 (patch) | |
| tree | 498da3a2fa94cb3105472e560b4c2aef3b788f6f /pdf | |
| parent | 5c5a13b31da451e47fe2df48aacf1d00377aaf64 (diff) | |
| download | mupdf-980e2932579e3ede636297b49baf12ad1bc8b2a7.tar.xz | |
Bug 693290: Harden pdf interpreter.
Various changes from zeniko to make the pdf interpreter cope better
with malformed files.
When running subobjects, catch the thrown errors to avoid upsetting
the clip stack.
When running a content stream, ensure that we don't underflow the
graphics states (in case of mismatched q/Q's). Here our patch
differs slightly from zeniko's original, as we pop any extra
ones off before returning.
Diffstat (limited to 'pdf')
| -rw-r--r-- | pdf/pdf_interpret.c | 36 |
1 files changed, 33 insertions, 3 deletions
diff --git a/pdf/pdf_interpret.c b/pdf/pdf_interpret.c index 6a2eab04..05494348 100644 --- a/pdf/pdf_interpret.c +++ b/pdf/pdf_interpret.c @@ -99,6 +99,7 @@ struct pdf_csi_s pdf_gstate *gstate; int gcap; int gtop; + int gbot; /* cookie support */ fz_cookie *cookie; @@ -306,6 +307,7 @@ static void pdf_begin_group(pdf_csi *csi, fz_rect bbox) { pdf_gstate *gstate = csi->gstate + csi->gtop; + fz_context *ctx = csi->dev->ctx; if (gstate->softmask) { @@ -318,7 +320,17 @@ pdf_begin_group(pdf_csi *csi, fz_rect bbox) fz_begin_mask(csi->dev, bbox, gstate->luminosity, softmask->colorspace, gstate->softmask_bc); - pdf_run_xobject(csi, NULL, softmask, fz_identity); + fz_try(ctx) + { + pdf_run_xobject(csi, NULL, softmask, fz_identity); + } + fz_catch(ctx) + { + /* FIXME: Ignore error - nasty, but if we throw from + * here the clip stack would be messed up. */ + if (csi->cookie) + csi->cookie->errors++; + } fz_end_mask(csi->dev); @@ -983,6 +995,7 @@ pdf_new_csi(pdf_document *xref, fz_device *dev, fz_matrix ctm, char *event, fz_c if (gstate) copy_state(ctx, &csi->gstate[0], gstate); csi->gtop = 0; + csi->gbot = 0; csi->cookie = cookie; } @@ -1044,7 +1057,7 @@ pdf_grestore(pdf_csi *csi) pdf_gstate *gs = csi->gstate + csi->gtop; int clip_depth = gs->clip_depth; - if (csi->gtop == 0) + if (csi->gtop <= csi->gbot) { fz_warn(ctx, "gstate underflow in content stream"); return; @@ -1376,7 +1389,18 @@ pdf_run_xobject(pdf_csi *csi, pdf_obj *resources, pdf_xobject *xobj, fz_matrix t fz_begin_mask(csi->dev, bbox, gstate->luminosity, softmask->colorspace, gstate->softmask_bc); - pdf_run_xobject(csi, resources, softmask, fz_identity); + fz_try(ctx) + { + pdf_run_xobject(csi, resources, softmask, fz_identity); + } + fz_catch(ctx) + { + /* FIXME: Ignore error - nasty, but if + * we throw from here the clip stack + * would be messed up */ + if (csi->cookie) + csi->cookie->errors++; + } fz_end_mask(csi->dev); pdf_drop_xobject(ctx, softmask); @@ -2717,6 +2741,7 @@ pdf_run_contents_stream(pdf_csi *csi, pdf_obj *rdb, fz_stream *file) fz_context *ctx = csi->dev->ctx; pdf_lexbuf *buf; int save_in_text; + int save_gbot; fz_var(buf); @@ -2727,6 +2752,8 @@ pdf_run_contents_stream(pdf_csi *csi, pdf_obj *rdb, fz_stream *file) pdf_lexbuf_init(ctx, buf, PDF_LEXBUF_SMALL); save_in_text = csi->in_text; csi->in_text = 0; + save_gbot = csi->gbot; + csi->gbot = csi->gtop; fz_try(ctx) { pdf_run_stream(csi, rdb, file, buf); @@ -2735,6 +2762,9 @@ pdf_run_contents_stream(pdf_csi *csi, pdf_obj *rdb, fz_stream *file) { fz_warn(ctx, "Content stream parsing error - rendering truncated"); } + while (csi->gtop > csi->gbot) + pdf_grestore(csi); + csi->gbot = save_gbot; csi->in_text = save_in_text; pdf_lexbuf_fin(buf); fz_free(ctx, buf); |