commit 3c378bb5e4ea8d4c9a5345083f278882322f9c9b

Author: Doran Moppert <dmoppert@redhat.com>

Date:   Fri Aug 12 13:58:57 2016 +0930

    Fix for hardlinks with .. in target path

     - factor cleanup_pathname into cleanup_pathname_fsobj

     - rename check_path_for_symlinks to check_path_fsobj for consistency

diff --git a/libarchive/archive_write_disk_posix.c b/libarchive/archive_write_disk_posix.c

index 66fc0f5..37261a5 100644

--- a/libarchive/archive_write_disk_posix.c

+++ b/libarchive/archive_write_disk_posix.c

@@ -326,13 +326,14 @@ struct archive_write_disk {

 #define HFS_BLOCKS(s)	((s) >> 12)

-static int check_path_for_symlinks(char *path, int *error_number, struct archive_string *error_string, int flags);

+static int	check_symlinks_fsobj(char *path, int *error_number, struct archive_string *error_string, int flags);

 static int	check_symlinks(struct archive_write_disk *);

 static int	create_filesystem_object(struct archive_write_disk *);

 static struct fixup_entry *current_fixup(struct archive_write_disk *, const char *pathname);

 #if defined(HAVE_FCHDIR) && defined(PATH_MAX)

 static void	edit_deep_directories(struct archive_write_disk *ad);

 #endif

+static int	cleanup_pathname_fsobj(char *path, int *error_number, struct archive_string *error_string, int flags);

 static int	cleanup_pathname(struct archive_write_disk *);

 static int	create_dir(struct archive_write_disk *, char *);

 static int	create_parent_dir(struct archive_write_disk *, char *);

@@ -1997,7 +1998,7 @@ create_filesystem_object(struct archive_write_disk *a)

 	const char *linkname;

 	mode_t final_mode, mode;

 	int r;

-	/* these for check_path_for_symlinks */

+	/* these for check_symlinks_fsobj */

 	char *linkname_copy;	/* non-const copy of linkname */

 	struct archive_string error_string;

 	int error_number;

@@ -2014,13 +2015,22 @@ create_filesystem_object(struct archive_write_disk *a)

 		if (linkname_copy == NULL) {

 		    return (EPERM);

 		}

-		r = check_path_for_symlinks(linkname_copy, &error_number, &error_string, a->flags);

-		free(linkname_copy);

+		/* TODO: consider using the cleaned-up path as the link target? */

+		r = cleanup_pathname_fsobj(linkname_copy, &error_number, &error_string, a->flags);

+		if (r != ARCHIVE_OK) {

+			archive_set_error(&a->archive, error_number, "%s", error_string.s);

+			free(linkname_copy);

+			/* EPERM is more appropriate than error_number for our callers */

+			return (EPERM);

+		}

+		r = check_symlinks_fsobj(linkname_copy, &error_number, &error_string, a->flags);

 		if (r != ARCHIVE_OK) {

 			archive_set_error(&a->archive, error_number, "%s", error_string.s);

+			free(linkname_copy);

 			/* EPERM is more appropriate than error_number for our callers */

 			return (EPERM);

 		}

+		free(linkname_copy);

 		r = link(linkname, a->name) ? errno : 0;

 		/*

 		 * New cpio and pax formats allow hardlink entries

@@ -2365,7 +2375,8 @@ current_fixup(struct archive_write_disk *a, const char *pathname)

  * Checks the given path to see if any elements along it are symlinks.  Returns

  * ARCHIVE_OK if there are none, otherwise puts an error in errmsg.

  */

-static int check_path_for_symlinks(char *path, int *error_number, struct archive_string *error_string, int flags)

+static int

+check_symlinks_fsobj(char *path, int *error_number, struct archive_string *error_string, int flags)

 {

 #if !defined(HAVE_LSTAT)

 	/* Platform doesn't have lstat, so we can't look for symlinks. */

@@ -2558,7 +2569,7 @@ check_symlinks(struct archive_write_disk *a)

 	int error_number;

 	int rc;

 	archive_string_init(&error_string);

-	rc = check_path_for_symlinks(a->name, &error_number, &error_string, a->flags);

+	rc = check_symlinks_fsobj(a->name, &error_number, &error_string, a->flags);

 	if (rc != ARCHIVE_OK) {

 		archive_set_error(&a->archive, error_number, "%s", error_string.s);

 	}

@@ -2640,15 +2651,17 @@ cleanup_pathname_win(struct archive_write_disk *a)

  * set) any '..' in the path.

  */

 static int

-cleanup_pathname(struct archive_write_disk *a)

+cleanup_pathname_fsobj(char *path, int *error_number, struct archive_string *error_string, int flags)

 {

 	char *dest, *src;

 	char separator = '\0';

-	dest = src = a->name;

+	dest = src = path;

 	if (*src == '\0') {

-		archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,

-		    "Invalid empty pathname");

+		if (error_number) *error_number = ARCHIVE_ERRNO_MISC;

+		if (error_string)

+			archive_string_sprintf(error_string,

+				"Invalid empty pathname");

 		return (ARCHIVE_FAILED);

 	}

@@ -2679,10 +2692,11 @@ cleanup_pathname(struct archive_write_disk *a)

 			} else if (src[1] == '.') {

 				if (src[2] == '/' || src[2] == '\0') {

 					/* Conditionally warn about '..' */

-					if (a->flags & ARCHIVE_EXTRACT_SECURE_NODOTDOT) {

-						archive_set_error(&a->archive,

-						    ARCHIVE_ERRNO_MISC,

-						    "Path contains '..'");

+					if (flags & ARCHIVE_EXTRACT_SECURE_NODOTDOT) {

+						if (error_number) *error_number = ARCHIVE_ERRNO_MISC;

+						if (error_string)

+							archive_string_sprintf(error_string,

+								"Path contains '..'");

 						return (ARCHIVE_FAILED);

 					}

 				}

@@ -2713,7 +2727,7 @@ cleanup_pathname(struct archive_write_disk *a)

 	 * We've just copied zero or more path elements, not including the

 	 * final '/'.

 	 */

-	if (dest == a->name) {

+	if (dest == path) {

 		/*

 		 * Nothing got copied.  The path must have been something

 		 * like '.' or '/' or './' or '/././././/./'.

@@ -2728,6 +2742,21 @@ cleanup_pathname(struct archive_write_disk *a)

 	return (ARCHIVE_OK);

 }

+static int

+cleanup_pathname(struct archive_write_disk *a)

+{

+	struct archive_string error_string;

+	int error_number;

+	int rc;

+	archive_string_init(&error_string);

+	rc = cleanup_pathname_fsobj(a->name, &error_number, &error_string, a->flags);

+	if (rc != ARCHIVE_OK) {

+		archive_set_error(&a->archive, error_number, "%s", error_string.s);

+	}

+	archive_string_free(&error_string);

+	return rc;

+}

+

 /*

  * Create the parent directory of the specified path, assuming path

  * is already in mutable storage.