From: Jeremy Harris <jgh146exb@wizmail.org>
Date: Sun, 29 Mar 2020 19:59:49 +0000 (+0100)
Subject: Dsearch: require absolute dirname
X-Git-Tag: exim-4_94_RC0~40
X-Git-Url: https://vcs.fsf.org/?a=commitdiff_plain;h=129a5d133927ff8fa4b3f941f83c022d2daf18f3;p=exim.git

Dsearch: require absolute dirname
---

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 8605fdc3b..b9d73ad3f 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -6770,8 +6770,13 @@ by default, but has an option to omit them (see section &<<SECTdbmbuild>>&).
 .next
 .cindex "lookup" "dsearch"
 .cindex "dsearch lookup type"
-&(dsearch)&: The given file must be a directory; this is searched for an entry
-whose name is the key by calling the &[lstat()]& function. The key may not
+&(dsearch)&: The given file must be an
+.new
+absolute
+.wen
+directory path; this is searched for an entry
+whose name is the key by calling the &[lstat()]& function.
+The key may not
 contain any forward slash characters. If &[lstat()]& succeeds, the result of
 the lookup is the name of the entry, which may be a file, directory,
 symbolic link, or any other kind of directory entry.
diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 7e5de8880..9de2e1194 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -93,6 +93,7 @@ JH/20 Taint checking: disallow use of tainted data for
       - the autoreply transport file, log and once options
       - file names used by the redirect router (including filter files)
       - named-queue names
+      - paths used by single-key lookups
       Previously this was permitted.
 
 JH/21 Bug 2501: Fix init call in the heimdal authenticator.  Previously it
@@ -159,6 +160,10 @@ JH/33 Fix the dsearch lookup to return an untainted result.  Previously the
 JH/34 Fix the readsocket expansion to not segfault when an empty "options"
       argument is supplied.
 
+JH/35 The dsearch lookup now requires that the directory is an absolute path.
+      Previously this was not checked, and nonempty relative paths made an
+      access under Exim's current working directory.
+
 
 Exim version 4.93
 -----------------
diff --git a/src/src/lookups/dsearch.c b/src/src/lookups/dsearch.c
index dba8422cc..07931ae4a 100644
--- a/src/src/lookups/dsearch.c
+++ b/src/src/lookups/dsearch.c
@@ -52,8 +52,11 @@ dsearch_check(void * handle, const uschar * filename, int modemask,
   uid_t * owners, gid_t * owngroups, uschar ** errmsg)
 {
 handle = handle;
-return lf_check_file(-1, filename, S_IFDIR, modemask, owners, owngroups,
-  "dsearch", errmsg) == 0;
+if (*filename == '/')
+  return lf_check_file(-1, filename, S_IFDIR, modemask, owners, owngroups,
+    "dsearch", errmsg) == 0;
+*errmsg = string_sprintf("dirname '%s' for dsearch is not absolute", filename);
+return FALSE;
 }
 
 
diff --git a/test/scripts/2500-dsearch/2500 b/test/scripts/2500-dsearch/2500
index 49e2a3761..040ce599e 100644
--- a/test/scripts/2500-dsearch/2500
+++ b/test/scripts/2500-dsearch/2500
@@ -6,6 +6,7 @@ fail:       ${lookup{TESTNUM.file_not_here}	dsearch{DIR/aux-fixed}{$value}{FAIL}
 fail:       ${lookup{TESTNUM.tst}		dsearch{DIR/dir_not_here}{$value}{FAIL}}
 fail(case): ${lookup{TESTNUM.TST}		dsearch{DIR/aux-fixed}{$value}{FAIL}}
 fail(case): ${lookup{TESTNUM.TST}		dsearch{DIR/AUX-fixed}{$value}{FAIL}}
+fail(path): ${lookup{TESTNUM.tst}		dsearch{.}{$value}{OTHER}}
 ****
 #
 1
diff --git a/test/stdout/2500 b/test/stdout/2500
index 8ff2378cc..3259e726c 100644
--- a/test/stdout/2500
+++ b/test/stdout/2500
@@ -3,4 +3,5 @@
 > Failed: failed to open TESTSUITE/dir_not_here for directory search: No such file or directory
 > fail(case): FAIL
 > Failed: failed to open TESTSUITE/AUX-fixed for directory search: No such file or directory
+> Failed: dirname '.' for dsearch is not absolute
 >