Patch from Vladimir:

1) fixed a bug that could crash df, mount, and umount applets if the root
    device name was longer then the word "root" (/dev/loop1 vs /dev/root) -
    2) severl functions needed static declaration in the umount applet
    3) update declaration for function in last_char_is() in libbb

libbb/chomp.c

@@ -32,7 +32,7 @@
 
 void chomp(char *s)
 {
-	char *lc = (char *)last_char_is(s, '\n');
+	char *lc = last_char_is(s, '\n');
 	
 	if(lc)
 		*lc = 0;

libbb/concat_path_file.c

@@ -11,9 +11,9 @@
 extern char *concat_path_file(const char *path, const char *filename)
 {
 	char *outbuf;
-	const char *lc;
+	char *lc;
 	
-	lc = last_char_is((char*)path, '/');
+	lc = last_char_is(path, '/');
 	if (filename[0] == '/')
 		filename++;
 	outbuf = xmalloc(strlen(path)+strlen(filename)+1+(lc==NULL));

libbb/find_root_device.c

@@ -28,26 +28,27 @@
 #include <stdio.h>
 #include <string.h>
 #include <dirent.h>
+#include <stdlib.h>
 #include "libbb.h"
 
 
 
-extern int find_real_root_device_name(char* name)
+extern char *find_real_root_device_name(const char* name)
 {
 	DIR *dir;
 	struct dirent *entry;
 	struct stat statBuf, rootStat;
-	char fileName[BUFSIZ];
+	char *fileName;
 
 	if (stat("/", &rootStat) != 0) {
 		error_msg("could not stat '/'");
-		return( FALSE);
+		return NULL;
 	}
 
 	dir = opendir("/dev");
 	if (!dir) {
 		error_msg("could not open '/dev'");
-		return( FALSE);
+		return NULL;
 	}
 
 	while((entry = readdir(dir)) != NULL) {
@@ -57,21 +58,20 @@ extern int find_real_root_device_name(char* name)
 		if (strcmp(entry->d_name, "..") == 0)
 			continue;
 
-		snprintf( fileName, strlen(name)+1, "/dev/%s", entry->d_name);
+		fileName = concat_path_file("/dev/", entry->d_name);
 
-		if (stat(fileName, &statBuf) != 0)
-			continue;
 		/* Some char devices have the same dev_t as block
 		 * devices, so make sure this is a block device */
-		if (! S_ISBLK(statBuf.st_mode))
-			continue;
-		if (statBuf.st_rdev == rootStat.st_rdev) {
-			strcpy(name, fileName); 
-			return ( TRUE);
+		if (stat(fileName, &statBuf) == 0 && 
+				S_ISBLK(statBuf.st_mode)!=0 &&
+				statBuf.st_rdev == rootStat.st_rdev) {
+			return fileName; 
 		}
+		free(fileName);
 	}
+	closedir(dir);
 
-	return( FALSE);
+	return NULL;
 }
 
 

libbb/last_char_is.c

@@ -25,9 +25,9 @@
  * underrun the buffer if the string length is 0.  Also avoids a possible
  * space-hogging inline of strlen() per usage.
  */
-char * last_char_is(char *s, int c)
+char * last_char_is(const char *s, int c)
 {
-	char *sret  = s+strlen(s)-1;
+	char *sret  = (char *)s+strlen(s)-1;
 	if (sret>=s && *sret == c) { 
 		return sret;
 	} else {

libbb/libbb.h

@@ -123,13 +123,9 @@ extern struct mntent *find_mount_point(const char *name, const char *table);
 extern void write_mtab(char* blockDevice, char* directory, 
 	char* filesystemType, long flags, char* string_flags);
 extern void erase_mtab(const char * name);
-extern void mtab_read(void);
-extern char *mtab_first(void **iter);
-extern char *mtab_next(void **iter);
-extern char *mtab_getinfo(const char *match, const char which);
 extern long atoi_w_units (const char *cp);
 extern pid_t* find_pid_by_name( char* pidName);
-extern int find_real_root_device_name(char* name);
+extern char *find_real_root_device_name(const char* name);
 extern char *get_line_from_file(FILE *file);
 extern void print_file(FILE *file);
 extern int print_file_by_name(char *filename);
@@ -218,7 +214,7 @@ int klogctl(int type, char * b, int len);
 char *xgetcwd(char *cwd);
 char *xreadlink(const char *path);
 char *concat_path_file(const char *path, const char *filename);
-char *last_char_is(char *s, int c);
+char *last_char_is(const char *s, int c);
 
 typedef struct ar_headers_s {
 	char *name;