Fix CVE-2019-19126:

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-19126
https://sourceware.org/bugzilla/show_bug.cgi?id=25204

Taken from upstream:
https://sourceware.org/git/?p=glibc.git;a=commit;h=37c90e117310728a4ad1eb998c0bbe7d79c4a398

diff --git a/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h b/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h
index 975cbe2..df2cdfd 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h
+++ b/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h
@@ -31,7 +31,8 @@
    environment variable, LD_PREFER_MAP_32BIT_EXEC.  */
 #define EXTRA_LD_ENVVARS \
   case 21:								  \
-    if (memcmp (envline, "PREFER_MAP_32BIT_EXEC", 21) == 0)		  \
+    if (!__libc_enable_secure						  \
+	&& memcmp (envline, "PREFER_MAP_32BIT_EXEC", 21) == 0)		  \
       GLRO(dl_x86_cpu_features).feature[index_arch_Prefer_MAP_32BIT_EXEC] \
 	|= bit_arch_Prefer_MAP_32BIT_EXEC;				  \
     break;
h'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=a44569899a54d18a70b62498bec3774f0be3f66b'>refs</a><a class='active' href='/guix/log/gnu/packages/patches/rw-igraph-0.10.patch'>log</a><a href='/guix/tree/gnu/packages/patches/rw-igraph-0.10.patch?id=a44569899a54d18a70b62498bec3774f0be3f66b'>tree</a><a href='/guix/commit/gnu/packages/patches/rw-igraph-0.10.patch?id=a44569899a54d18a70b62498bec3774f0be3f66b'>commit</a><a href='/guix/diff/gnu/packages/patches/rw-igraph-0.10.patch?id=a44569899a54d18a70b62498bec3774f0be3f66b'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/patches/rw-igraph-0.10.patch'>
<input type='hidden' name='id' value='a44569899a54d18a70b62498bec3774f0be3f66b'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=a44569899a54d18a70b62498bec3774f0be3f66b'>root</a>/<a href='/guix/log/gnu?id=a44569899a54d18a70b62498bec3774f0be3f66b'>gnu</a>/<a href='/guix/log/gnu/packages?id=a44569899a54d18a70b62498bec3774f0be3f66b'>packages</a>/<a href='/guix/log/gnu/packages/patches?id=a44569899a54d18a70b62498bec3774f0be3f66b'>patches</a>/<a href='/guix/log/gnu/packages/patches/rw-igraph-0.10.patch?id=a44569899a54d18a70b62498bec3774f0be3f66b'>rw-igraph-0.10.patch</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/patches/rw-igraph-0.10.patch?id=a44569899a54d18a70b62498bec3774f0be3f66b&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-01-27 14:08:55 -0500'>2023-01-27</span></td><td><a href='/guix/commit/gnu/packages/patches/rw-igraph-0.10.patch?id=0b1fae08d0b005380ff6c97c88abf5e6889f43f6'>gnu: rw: Update to 0.9 and apply a patch to build with igraph &gt;= 0.10.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/patches/rw-igraph-0.10.patch: New file.
* gnu/local.mk: Register it.
* gnu/packages/graph.scm (rw): Update to 0.9.  Apply patch.
</span></span></td><td>Maxim Cournoyer</td></tr>