diff --git a/sysfs.c b/sysfs.c
index d28e21a..f8a9f0b 100644
--- a/sysfs.c
+++ b/sysfs.c
@@ -27,6 +27,8 @@
 #include	<dirent.h>
 #include	<ctype.h>
 
+#define MAX_SYSFS_PATH_LEN	120
+
 int load_sys(char *path, char *buf, int len)
 {
 	int fd = open(path, O_RDONLY);
@@ -59,15 +61,15 @@ void sysfs_free(struct mdinfo *sra)
 
 int sysfs_open(char *devnm, char *devname, char *attr)
 {
-	char fname[50];
+	char fname[MAX_SYSFS_PATH_LEN];
 	int fd;
 
-	sprintf(fname, "/sys/block/%s/md/", devnm);
+	snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/", devnm);
 	if (devname) {
-		strcat(fname, devname);
-		strcat(fname, "/");
+		strncat(fname, devname, MAX_SYSFS_PATH_LEN - strlen(fname));
+		strncat(fname, "/", MAX_SYSFS_PATH_LEN - strlen(fname));
 	}
-	strcat(fname, attr);
+	strncat(fname, attr, MAX_SYSFS_PATH_LEN - strlen(fname));
 	fd = open(fname, O_RDWR);
 	if (fd < 0 && errno == EACCES)
 		fd = open(fname, O_RDONLY);
@@ -392,15 +394,17 @@ unsigned long long get_component_size(int fd)
 	 * This returns in units of sectors.
 	 */
 	struct stat stb;
-	char fname[50];
+	char fname[MAX_SYSFS_PATH_LEN];
 	int n;
 	if (fstat(fd, &stb))
 		return 0;
 	if (major(stb.st_rdev) != (unsigned)get_mdp_major())
-		sprintf(fname, "/sys/block/md%d/md/component_size",
+		snprintf(fname, MAX_SYSFS_PATH_LEN,
+			"/sys/block/md%d/md/component_size",
 			(int)minor(stb.st_rdev));
 	else
-		sprintf(fname, "/sys/block/md_d%d/md/component_size",
+		snprintf(fname, MAX_SYSFS_PATH_LEN,
+			"/sys/block/md_d%d/md/component_size",
 			(int)minor(stb.st_rdev)>>MdpMinorShift);
 	fd = open(fname, O_RDONLY);
 	if (fd < 0)
@@ -416,11 +420,11 @@ unsigned long long get_component_size(int fd)
 int sysfs_set_str(struct mdinfo *sra, struct mdinfo *dev,
 		  char *name, char *val)
 {
-	char fname[50];
+	char fname[MAX_SYSFS_PATH_LEN];
 	unsigned int n;
 	int fd;
 
-	sprintf(fname, "/sys/block/%s/md/%s/%s",
+	snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/%s/%s",
 		sra->sys_name, dev?dev->sys_name:"", name);
 	fd = open(fname, O_WRONLY);
 	if (fd < 0)
@@ -453,11 +457,11 @@ int sysfs_set_num_signed(struct mdinfo *sra, struct mdinfo *dev,
 
 int sysfs_uevent(struct mdinfo *sra, char *event)
 {
-	char fname[50];
+	char fname[MAX_SYSFS_PATH_LEN];
 	int n;
 	int fd;
 
-	sprintf(fname, "/sys/block/%s/uevent",
+	snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/uevent",
 		sra->sys_name);
 	fd = open(fname, O_WRONLY);
 	if (fd < 0)
@@ -474,10 +478,10 @@ int sysfs_uevent(struct mdinfo *sra, char *event)
 
 int sysfs_attribute_available(struct mdinfo *sra, struct mdinfo *dev, char *name)
 {
-	char fname[50];
+	char fname[MAX_SYSFS_PATH_LEN];
 	struct stat st;
 
-	sprintf(fname, "/sys/block/%s/md/%s/%s",
+	snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/%s/%s",
 		sra->sys_name, dev?dev->sys_name:"", name);
 
 	return stat(fname, &st) == 0;
@@ -486,10 +490,10 @@ int sysfs_attribute_available(struct mdinfo *sra, struct mdinfo *dev, char *name
 int sysfs_get_fd(struct mdinfo *sra, struct mdinfo *dev,
 		       char *name)
 {
-	char fname[50];
+	char fname[MAX_SYSFS_PATH_LEN];
 	int fd;
 
-	sprintf(fname, "/sys/block/%s/md/%s/%s",
+	snprintf(fname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/%s/%s",
 		sra->sys_name, dev?dev->sys_name:"", name);
 	fd = open(fname, O_RDWR);
 	if (fd < 0)