diff --git a/drivers/isdn/hardware/eicon/divasmain.c b/drivers/isdn/hardware/eicon/divasmain.c
index dae2e83dd5e86604a819c39f2b897467f5396f2f..91fc92c01afe84930dc5bd5838a9db52ebb1c6d5 100644
--- a/drivers/isdn/hardware/eicon/divasmain.c
+++ b/drivers/isdn/hardware/eicon/divasmain.c
@@ -185,7 +185,7 @@ void diva_log_info(unsigned char *format, ...)
 	unsigned char line[160];
 
 	va_start(args, format);
-	vsprintf(line, format, args);
+	vsnprintf(line, sizeof(line), format, args);
 	va_end(args);
 
 	printk(KERN_INFO "%s: %s\n", DRIVERLNAME, line);
diff --git a/drivers/isdn/hisax/hisax_isac.c b/drivers/isdn/hisax/hisax_isac.c
index 81eac344bb0325fcf615a5808e52fb87401eb640..d0fefcf999cb7226b89e81c50021cfc1be263ee9 100644
--- a/drivers/isdn/hisax/hisax_isac.c
+++ b/drivers/isdn/hisax/hisax_isac.c
@@ -433,7 +433,7 @@ static void l1m_debug(struct FsmInst *fi, char *fmt, ...)
 	char buf[256];
 	
 	va_start(args, fmt);
-	vsprintf(buf, fmt, args);
+	vsnprintf(buf, sizeof(buf), fmt, args);
 	DBG(DBG_L1M, "%s", buf);
 	va_end(args);
 }
diff --git a/drivers/isdn/hisax/st5481_d.c b/drivers/isdn/hisax/st5481_d.c
index 1d8c2618366c385c4ea285765922aae12603a09c..b8c4855cc8894c700169184e3b04ae5500dcf86c 100644
--- a/drivers/isdn/hisax/st5481_d.c
+++ b/drivers/isdn/hisax/st5481_d.c
@@ -173,7 +173,7 @@ static void l1m_debug(struct FsmInst *fi, char *fmt, ...)
 	char buf[256];
 	
 	va_start(args, fmt);
-	vsprintf(buf, fmt, args);
+	vsnprintf(buf, sizeof(buf), fmt, args);
 	DBG(8, "%s", buf);
 	va_end(args);
 }
@@ -275,7 +275,7 @@ static void dout_debug(struct FsmInst *fi, char *fmt, ...)
 	char buf[256];
 	
 	va_start(args, fmt);
-	vsprintf(buf, fmt, args);
+	vsnprintf(buf, sizeof(buf), fmt, args);
 	DBG(0x2, "%s", buf);
 	va_end(args);
 }