diff --git a/src/backend/utils/adt/genfile.c b/src/backend/utils/adt/genfile.c
index 9e707c5d8e4473718a15314114e6f837d8e650f3..2936050d10529072b7f882dbc824f2064aaf02b9 100644
--- a/src/backend/utils/adt/genfile.c
+++ b/src/backend/utils/adt/genfile.c
@@ -9,7 +9,7 @@
* Author: Andreas Pflug <pgadmin@pse-consulting.de>
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/genfile.c,v 1.2 2005/08/12 18:23:54 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/genfile.c,v 1.3 2005/08/12 21:07:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -46,33 +46,19 @@ typedef struct
static char *
check_and_make_absolute(text *arg)
{
- int filename_len = VARSIZE(arg) - VARHDRSZ;
- char *filename = palloc(filename_len + 1);
+ int input_len = VARSIZE(arg) - VARHDRSZ;
+ char *filename = palloc(input_len + 1);
- memcpy(filename, VARDATA(arg), filename_len);
- filename[filename_len] = '\0';
-
- canonicalize_path(filename);
- filename_len = strlen(filename); /* recompute */
-
- /*
- * Prevent reference to the parent directory.
- * "..a.." is a valid file name though.
- *
- * XXX this is BROKEN because it fails to prevent "C:.." on Windows.
- * Need access to "skip_drive" functionality to do it right. (There
- * is no actual security hole because we'll prepend the DataDir below,
- * resulting in a just-plain-broken path, but we should give the right
- * error message instead.)
- */
- if (strcmp(filename, "..") == 0 || /* whole */
- strncmp(filename, "../", 3) == 0 || /* beginning */
- strstr(filename, "/../") != NULL || /* middle */
- (filename_len >= 3 &&
- strcmp(filename + filename_len - 3, "/..") == 0)) /* end */
- ereport(ERROR,
- (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
- (errmsg("reference to parent directory (\"..\") not allowed"))));
+ memcpy(filename, VARDATA(arg), input_len);
+ filename[input_len] = '\0';
+
+ canonicalize_path(filename); /* filename can change length here */
+
+ /* Disallow ".." in the path */
+ if (path_contains_parent_reference(filename))
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ (errmsg("reference to parent directory (\"..\") not allowed"))));
if (is_absolute_path(filename))
{
@@ -90,7 +76,7 @@ check_and_make_absolute(text *arg)
}
else
{
- char *absname = palloc(strlen(DataDir) + filename_len + 2);
+ char *absname = palloc(strlen(DataDir) + strlen(filename) + 2);
sprintf(absname, "%s/%s", DataDir, filename);
pfree(filename);
return absname;
diff --git a/src/include/port.h b/src/include/port.h
index 95e5531c931430091df22d00a429daf1e6440835..ce261d9f050a357f15758cd1d81a0c4d147f11b3 100644
--- a/src/include/port.h
+++ b/src/include/port.h
@@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/port.h,v 1.80 2005/08/02 19:02:32 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/port.h,v 1.81 2005/08/12 21:07:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -32,6 +32,7 @@ extern void join_path_components(char *ret_path,
const char *head, const char *tail);
extern void canonicalize_path(char *path);
extern void make_native_path(char *path);
+extern bool path_contains_parent_reference(const char *path);
extern const char *get_progname(const char *argv0);
extern void get_share_path(const char *my_exec_path, char *ret_path);
extern void get_etc_path(const char *my_exec_path, char *ret_path);
diff --git a/src/port/path.c b/src/port/path.c
index 41a526f170f89676a08469666636f26018ad98e4..7e37bede7eaaeaebed51f3ea7f666c1997d354d2 100644
--- a/src/port/path.c
+++ b/src/port/path.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/port/path.c,v 1.56 2005/08/12 19:43:32 momjian Exp $
+ * $PostgreSQL: pgsql/src/port/path.c,v 1.57 2005/08/12 21:07:53 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -225,7 +225,9 @@ void
canonicalize_path(char *path)
{
char *p, *to_p;
+ char *spath;
bool was_sep = false;
+ int pending_strips;
#ifdef WIN32
/*
@@ -277,30 +279,89 @@ canonicalize_path(char *path)
/*
* Remove any trailing uses of "." and process ".." ourselves
+ *
+ * Note that "/../.." should reduce to just "/", while "../.." has to
+ * be kept as-is. In the latter case we put back mistakenly trimmed
+ * ".." components below. Also note that we want a Windows drive spec
+ * to be visible to trim_directory(), but it's not part of the logic
+ * that's looking at the name components; hence distinction between
+ * path and spath.
*/
+ spath = skip_drive(path);
+ pending_strips = 0;
for (;;)
{
- int len = strlen(path);
+ int len = strlen(spath);
- if (len > 2 && strcmp(path + len - 2, "/.") == 0)
+ if (len >= 2 && strcmp(spath + len - 2, "/.") == 0)
trim_directory(path);
- /*
- * Process only a single trailing "..", and only if ".." does
- * not preceed it.
- * So, we only deal with "/usr/local/..", not with "/usr/local/../..".
- * We don't handle the even more complex cases, like
- * "usr/local/../../..".
- */
- else if (len > 3 && strcmp(path + len - 3, "/..") == 0 &&
- (len != 5 || strcmp(path, "../..") != 0) &&
- (len < 6 || strcmp(path + len - 6, "/../..") != 0))
+ else if (strcmp(spath, ".") == 0)
+ {
+ /* Want to leave "." alone, but "./.." has to become ".." */
+ if (pending_strips > 0)
+ *spath = '\0';
+ break;
+ }
+ else if ((len >= 3 && strcmp(spath + len - 3, "/..") == 0) ||
+ strcmp(spath, "..") == 0)
+ {
+ trim_directory(path);
+ pending_strips++;
+ }
+ else if (pending_strips > 0 && *spath != '\0')
{
+ /* trim a regular directory name cancelled by ".." */
trim_directory(path);
- trim_directory(path); /* remove directory above */
+ pending_strips--;
+ /* foo/.. should become ".", not empty */
+ if (*spath == '\0')
+ strcpy(spath, ".");
}
else
break;
}
+
+ if (pending_strips > 0)
+ {
+ /*
+ * We could only get here if path is now totally empty (other than
+ * a possible drive specifier on Windows).
+ * We have to put back one or more ".."'s that we took off.
+ */
+ while (--pending_strips > 0)
+ strcat(path, "../");
+ strcat(path, "..");
+ }
+}
+
+/*
+ * Detect whether a path contains any parent-directory references ("..")
+ *
+ * The input *must* have been put through canonicalize_path previously.
+ *
+ * This is a bit tricky because we mustn't be fooled by "..a.." (legal)
+ * nor "C:.." (legal on Unix but not Windows).
+ */
+bool
+path_contains_parent_reference(const char *path)
+{
+ int path_len;
+
+ path = skip_drive(path); /* C: shouldn't affect our conclusion */
+
+ path_len = strlen(path);
+
+ /*
+ * ".." could be the whole path; otherwise, if it's present it must
+ * be at the beginning, in the middle, or at the end.
+ */
+ if (strcmp(path, "..") == 0 ||
+ strncmp(path, "../", 3) == 0 ||
+ strstr(path, "/../") != NULL ||
+ (path_len >= 3 && strcmp(path + path_len - 3, "/..") == 0))
+ return true;
+
+ return false;
}