6459526 *rm* -r core dumps when attempting to remove a dir containing a hard link loop

2 files changed, 32 insertions, 11 deletions

diff --git a/usr/src/cmd/rm/Makefile b/usr/src/cmd/rm/Makefile
index d1346e02d4..5bceb7cbbe 100644
--- a/usr/src/cmd/rm/Makefile
+++ b/usr/src/cmd/rm/Makefile
@@ -2,9 +2,8 @@
 # CDDL HEADER START
 #
 # The contents of this file are subject to the terms of the
-# Common Development and Distribution License, Version 1.0 only
-# (the "License").  You may not use this file except in compliance
-# with the License.
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
 #
 # You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 # or http://www.opensolaris.org/os/licensing.
@@ -22,7 +21,7 @@
 #
 #ident	"%Z%%M%	%I%	%E% SMI"
 #
-# Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
+# Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 # Use is subject to license terms.
 #
 
@@ -34,6 +33,7 @@ include ../Makefile.cmd
 CFLAGS += $(CCVERBOSE)
 $(XPG4) := CFLAGS += -DXPG4
 CPPFLAGS += -D_FILE_OFFSET_BITS=64
+LDLIBS += -lcmdutils
 
 .KEEP_STATE:
 
diff --git a/usr/src/cmd/rm/rm.c b/usr/src/cmd/rm/rm.c
index bbdbadf588..bd53d48b75 100644
--- a/usr/src/cmd/rm/rm.c
+++ b/usr/src/cmd/rm/rm.c
@@ -18,15 +18,15 @@
  *
  * CDDL HEADER END
  */
-/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
-/*	  All Rights Reserved  	*/
-
 
 /*
  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
+/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
+/*	All Rights Reserved   */
+
 #pragma ident	"%Z%%M%	%I%	%E% SMI"
 
 /*
@@ -46,6 +46,8 @@
 #include <stdlib.h>
 #include <errno.h>
 #include <sys/resource.h>
+#include <sys/avl.h>
+#include <libcmdutils.h>
 
 #define	ARGCNT		5		/* Number of arguments */
 #define	CHILD		0
@@ -87,6 +89,7 @@ static rlim_t	maxfiles;	/* maximum number of open files */
 static int	first_dir = 1;	/* flag set when first trying to remove a dir */
 	/* flag set when can't get dev/inode of a parent dir */
 static int	parent_err = 0;
+static avl_tree_t *tree;	/* tree to keep track of nodes visited */
 
 struct dir_id {
 	dev_t	dev;
@@ -168,10 +171,11 @@ main(int argc, char *argv[])
 		maxfiles = rl.rlim_cur - 2;
 
 	while (argc-- > 0) {
+		tree = NULL;
 		rm(*argv, 1);
 		argv++;
+		destroy_tree(tree);
 	}
-
 	cleanup();
 	return (errcode ? 2 : 0);
 	/* NOTREACHED */
@@ -239,7 +243,6 @@ rm(char *path, int first)
 		undir(path, first, buffer.st_dev, buffer.st_ino);
 		return;
 	}
-
 	filepath = get_filename(path);
 
 	/*
@@ -329,6 +332,7 @@ undir(char *path, int first, dev_t dev, ino_t ino)
 	DIR	*name;
 	struct dirent *direct;
 	int	ismypath;
+	int	ret;
 	int	chdir_failed = 0;
 	size_t	len;
 
@@ -386,6 +390,25 @@ undir(char *path, int first, dev_t dev, ino_t ino)
 #endif
 
 	/*
+	 * Add this node to the search tree so we don't
+	 * get into a endless loop. If the add fails then
+	 * we have visited this node before.
+	 */
+	ret = add_tnode(&tree, dev, ino);
+	if (ret != 1) {
+		if (ret == 0) {
+			(void) fprintf(stderr,
+			    gettext("rm: cycle detected for %s\n"),
+			    fullpath);
+		} else if (ret == -1) {
+			perror("rm");
+		}
+		errcode++;
+		pop_name(first);
+		return;
+	}
+
+	/*
 	 * Open the directory for reading.
 	 */
 	if ((name = opendir(path)) == NULL) {
@@ -718,7 +741,6 @@ static void
 pop_name(int first)
 {
 	char *slash;
-
 	if (first) {
 		*fullpath = '\0';
 		return;
@@ -941,7 +963,6 @@ check_homedir(void)
 
 static void
 cleanup(void) {
-
 	struct dir_id *lastdir, *curdir;
 
 	curdir = homedir.next;