From f70ab2044429fe4b991801476ea3f4b4a5c0cdf4 Mon Sep 17 00:00:00 2001
From: Julian Smith <jules@op59.net>
Date: Wed, 6 Nov 2019 11:46:10 +0000
Subject: [PATCH 1/2] Bug 701843: avoid divide by zero caused by custom
 resolution being too low.

Fixes:
    ./sanbin/gs -dBATCH -dNOPAUSE -dSAFER -r8 -dNOCIE -dFitPage -sOutputFile=tmp -sDEVICE=eps9mid  ../bug-701843.pdf
---
 devices/gdevepsn.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/devices/gdevepsn.c b/devices/gdevepsn.c
index 49faaf3d7..3e5388322 100644
--- a/devices/gdevepsn.c
+++ b/devices/gdevepsn.c
@@ -159,10 +159,10 @@ eps_print_page(gx_device_printer *pdev, gp_file *prn_stream, int y_9pin_high,
         int line_size = gdev_mem_bytes_per_scan_line((gx_device *)pdev);
         /* Note that in_size is a multiple of 8. */
         int in_size = line_size * (8 * in_y_mult);
-        byte *buf1 = (byte *)gs_malloc(pdev->memory, in_size, 1, "eps_print_page(buf1)");
-        byte *buf2 = (byte *)gs_malloc(pdev->memory, in_size, 1, "eps_print_page(buf2)");
-        byte *in = buf1;
-        byte *out = buf2;
+        byte *buf1;
+        byte *buf2;
+        byte *in;
+        byte *out;
         int out_y_mult = (y_24pin ? 3 : 1);
         int x_dpi = (int)pdev->x_pixels_per_inch;
         char start_graphics =
@@ -174,6 +174,17 @@ eps_print_page(gx_device_printer *pdev, gp_file *prn_stream, int y_9pin_high,
         int bytes_per_space = dots_per_space * out_y_mult;
         int tab_min_pixels = x_dpi * MIN_TAB_10THS / 10;
         int skip = 0, lnum = 0, pass, ypass;
+
+        if (bytes_per_space == 0) {
+            /* This avoids divide by zero later on, bug 701843. */
+            return_error(gs_error_rangecheck);
+        }
+
+        buf1 = (byte *)gs_malloc(pdev->memory, in_size, 1, "eps_print_page(buf1)");
+        buf2 = (byte *)gs_malloc(pdev->memory, in_size, 1, "eps_print_page(buf2)");
+        in = buf1;
+        out = buf2;
+
 
         /* Check allocations */
         if ( buf1 == 0 || buf2 == 0 )

diff --git a/devices/gdevepsc.c b/devices/gdevepsc.c
--- a/devices/gdevepsc.c
+++ b/devices/gdevepsc.c
@@ -174,13 +174,7 @@
     int y_mult = (y_24pin ? 3 : 1);
     int line_size = (pdev->width + 7) >> 3;     /* always mono */
     int in_size = line_size * (8 * y_mult);
-    byte *in =
-        (byte *) gs_malloc(pdev->memory, in_size + 1, 1,
-                           "epsc_print_page(in)");
     int out_size = ((pdev->width + 7) & -8) * y_mult;
-    byte *out =
-        (byte *) gs_malloc(pdev->memory, out_size + 1, 1,
-                           "epsc_print_page(out)");
     int x_dpi = (int)pdev->x_pixels_per_inch;
     char start_graphics = (char)
         ((y_24pin ? graphics_modes_24 : graphics_modes_9)[x_dpi / 60]);
@@ -195,6 +189,20 @@
     int color_line_size, color_in_size;
     int spare_bits = (pdev->width % 8); /* left over bits to go to margin */
     int whole_bits = pdev->width - spare_bits;
+    byte *out;
+    byte *in;
+
+    if (bytes_per_space == 0) {
+        /* This avoids divide by zero later on, bug 701843. */
+        return_error(gs_error_rangecheck);
+    }
+
+    in =
+        (byte *) gs_malloc(pdev->memory, in_size + 1, 1,
+                           "epsc_print_page(in)");
+    out =
+        (byte *) gs_malloc(pdev->memory, out_size + 1, 1,
+                           "epsc_print_page(out)");
 
     /* Check allocations */
     if (in == 0 || out == 0) {