Refuse to extract an entry from an archive on top of the archive being read.

(This is the converse of the "don't add an archive to itself".)

4 files changed, 34 insertions, 3 deletions

diff --git a/lib/libarchive/archive_read_open_fd.c b/lib/libarchive/archive_read_open_fd.c
index cab1f9f..e3b2527 100644
--- a/lib/libarchive/archive_read_open_fd.c
+++ b/lib/libarchive/archive_read_open_fd.c
@@ -27,12 +27,14 @@
 #include "archive_platform.h"
 __FBSDID("$FreeBSD$");
 
+#include <sys/stat.h>
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #include "archive.h"
+#include "archive_private.h"
 
 struct read_fd_data {
 	int	 fd;
@@ -63,9 +65,16 @@ archive_read_open_fd(struct archive *a, int fd, size_t block_size)
 static int
 file_open(struct archive *a, void *client_data)
 {
-	(void)client_data; /* UNUSED */
-	(void)a; /* UNUSED */
+	struct read_fd_data *mine = client_data;
+	struct stat st;
+
+	if (fstat(mine->fd, &st) != 0) {
+		archive_set_error(a, errno, "Can't stat fd %d", mine->fd);
+		return (ARCHIVE_FATAL);
+	}
 
+	a->skip_file_dev = st.st_dev;
+	a->skip_file_ino = st.st_ino;
 	return (ARCHIVE_OK);
 }
 
diff --git a/lib/libarchive/archive_read_open_file.c b/lib/libarchive/archive_read_open_file.c
index fa30bbb..54e1239 100644
--- a/lib/libarchive/archive_read_open_file.c
+++ b/lib/libarchive/archive_read_open_file.c
@@ -27,6 +27,7 @@
 #include "archive_platform.h"
 __FBSDID("$FreeBSD$");
 
+#include <sys/stat.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdlib.h>
@@ -34,6 +35,7 @@ __FBSDID("$FreeBSD$");
 #include <unistd.h>
 
 #include "archive.h"
+#include "archive_private.h"
 
 struct read_file_data {
 	int	 fd;
@@ -77,6 +79,7 @@ static int
 file_open(struct archive *a, void *client_data)
 {
 	struct read_file_data *mine = client_data;
+	struct stat st;
 
 	mine->buffer = malloc(mine->block_size);
 	if (*mine->filename != 0)
@@ -88,6 +91,14 @@ file_open(struct archive *a, void *client_data)
 		    mine->filename);
 		return (ARCHIVE_FATAL);
 	}
+	if (fstat(mine->fd, &st) == 0) {
+		a->skip_file_dev = st.st_dev;
+		a->skip_file_ino = st.st_ino;
+	} else {
+		archive_set_error(a, errno, "Can't stat '%s'",
+		    mine->filename);
+		return (ARCHIVE_FATAL);
+	}
 	return (0);
 }
 
diff --git a/lib/libarchive/archive_read_open_filename.c b/lib/libarchive/archive_read_open_filename.c
index fa30bbb..54e1239 100644
--- a/lib/libarchive/archive_read_open_filename.c
+++ b/lib/libarchive/archive_read_open_filename.c
@@ -27,6 +27,7 @@
 #include "archive_platform.h"
 __FBSDID("$FreeBSD$");
 
+#include <sys/stat.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdlib.h>
@@ -34,6 +35,7 @@ __FBSDID("$FreeBSD$");
 #include <unistd.h>
 
 #include "archive.h"
+#include "archive_private.h"
 
 struct read_file_data {
 	int	 fd;
@@ -77,6 +79,7 @@ static int
 file_open(struct archive *a, void *client_data)
 {
 	struct read_file_data *mine = client_data;
+	struct stat st;
 
 	mine->buffer = malloc(mine->block_size);
 	if (*mine->filename != 0)
@@ -88,6 +91,14 @@ file_open(struct archive *a, void *client_data)
 		    mine->filename);
 		return (ARCHIVE_FATAL);
 	}
+	if (fstat(mine->fd, &st) == 0) {
+		a->skip_file_dev = st.st_dev;
+		a->skip_file_ino = st.st_ino;
+	} else {
+		archive_set_error(a, errno, "Can't stat '%s'",
+		    mine->filename);
+		return (ARCHIVE_FATAL);
+	}
 	return (0);
 }
 
diff --git a/lib/libarchive/archive_write.c b/lib/libarchive/archive_write.c
index f910f14..eded384 100644
--- a/lib/libarchive/archive_write.c
+++ b/lib/libarchive/archive_write.c
@@ -189,7 +189,7 @@ archive_write_header(struct archive *a, struct archive_entry *entry)
 
 	if (archive_entry_dev(entry) == a->skip_file_dev &&
 	    archive_entry_ino(entry) == a->skip_file_ino) {
-		archive_set_error(a, 0, "Can't add archive to itself.");
+		archive_set_error(a, 0, "Can't add archive to itself");
 		return (ARCHIVE_WARN);
 	}