Copied from Debian.

From: Petr Stodulka <pstodulk@redhat.com>
Date: Mon, 14 Sep 2015 18:23:17 +0200
Subject: Upstream fix for heap overflow
Bug-Debian: https://bugs.debian.org/802162
Bug-RedHat: https://bugzilla.redhat.com/show_bug.cgi?id=1260944
Origin: https://bugzilla.redhat.com/attachment.cgi?id=1073002
Forwarded: yes

---
 crypt.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

--- a/crypt.c
+++ b/crypt.c
@@ -465,7 +465,17 @@
     GLOBAL(pInfo->encrypted) = FALSE;
     defer_leftover_input(__G);
     for (n = 0; n < RAND_HEAD_LEN; n++) {
-        b = NEXTBYTE;
+        /* 2012-11-23 SMS.  (OUSPG report.)
+         * Quit early if compressed size < HEAD_LEN.  The resulting
+         * error message ("unable to get password") could be improved,
+         * but it's better than trying to read nonexistent data, and
+         * then continuing with a negative G.csize.  (See
+         * fileio.c:readbyte()).
+         */
+        if ((b = NEXTBYTE) == (ush)EOF)
+        {
+            return PK_ERR;
+        }
         h[n] = (uch)b;
         Trace((stdout, " (%02x)", h[n]));
     }
15a7eec81f41a4163a3230d0d8bbbfeb0a5ed'>refs</a><a class='active' href='/guix/log/gnu/packages/debian.scm'>log</a><a href='/guix/tree/gnu/packages/debian.scm?id=83715a7eec81f41a4163a3230d0d8bbbfeb0a5ed'>tree</a><a href='/guix/commit/gnu/packages/debian.scm?id=83715a7eec81f41a4163a3230d0d8bbbfeb0a5ed'>commit</a><a href='/guix/diff/gnu/packages/debian.scm?id=83715a7eec81f41a4163a3230d0d8bbbfeb0a5ed'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/debian.scm'>
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<div class='path'>path: <a href='/guix/log/?id=83715a7eec81f41a4163a3230d0d8bbbfeb0a5ed'>root</a>/<a href='/guix/log/gnu?id=83715a7eec81f41a4163a3230d0d8bbbfeb0a5ed'>gnu</a>/<a href='/guix/log/gnu/packages?id=83715a7eec81f41a4163a3230d0d8bbbfeb0a5ed'>packages</a>/<a href='/guix/log/gnu/packages/debian.scm?id=83715a7eec81f41a4163a3230d0d8bbbfeb0a5ed'>debian.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages/debian.scm?id=83715a7eec81f41a4163a3230d0d8bbbfeb0a5ed&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2018-12-01 23:34:43 +0200'>2018-12-01</span></td><td><a href='/guix/commit/gnu/packages/debian.scm?id=a0e813725ee73f3638078fb99c003e7abe92a5be'>gnu: debootstrap: Update to 1.0.111.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2018-12-01 23:34:43 +0200'>2018-12-01</span></td><td><a href='/guix/commit/gnu/packages/debian.scm?id=7111ea0d588aca0cdd8ddd204919effa2f2d8283'>gnu: debootstrap: Update build.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2018-11-04 12:00:13 +0200'>2018-11-04</span></td><td><a href='/guix/commit/gnu/packages/debian.scm?id=f909e2179715ea1cf7d381810c2de5dcfedfb45e'>gnu: debian-archive-keyring: Update to 2018.1.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2018-11-04 12:00:10 +0200'>2018-11-04</span></td><td><a href='/guix/commit/gnu/packages/debian.scm?id=d4b5e4bb7377a31196b392c93b0072aed9cc969a'>gnu: debootstrap: Update to 1.0.109.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>