pstore: Use scnprintf() in pstore_mkfile()

No guarantees that the names will not exceed the
name buffer with future adjustments.
Signed-off-by: NMark Salyzyn <salyzyn@android.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NTony Luck <tony.luck@intel.com>

fs/pstore/inode.c

@@ -338,32 +338,35 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
 
 	switch (type) {
 	case PSTORE_TYPE_DMESG:
-		sprintf(name, "dmesg-%s-%lld%s", psname, id,
-						compressed ? ".enc.z" : "");
+		scnprintf(name, sizeof(name), "dmesg-%s-%lld%s",
+			  psname, id, compressed ? ".enc.z" : "");
 		break;
 	case PSTORE_TYPE_CONSOLE:
-		sprintf(name, "console-%s-%lld", psname, id);
+		scnprintf(name, sizeof(name), "console-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_FTRACE:
-		sprintf(name, "ftrace-%s-%lld", psname, id);
+		scnprintf(name, sizeof(name), "ftrace-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_MCE:
-		sprintf(name, "mce-%s-%lld", psname, id);
+		scnprintf(name, sizeof(name), "mce-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_PPC_RTAS:
-		sprintf(name, "rtas-%s-%lld", psname, id);
+		scnprintf(name, sizeof(name), "rtas-%s-%lld", psname, id);
 		break;
 	case PSTORE_TYPE_PPC_OF:
-		sprintf(name, "powerpc-ofw-%s-%lld", psname, id);
+		scnprintf(name, sizeof(name), "powerpc-ofw-%s-%lld",
+			  psname, id);
 		break;
 	case PSTORE_TYPE_PPC_COMMON:
-		sprintf(name, "powerpc-common-%s-%lld", psname, id);
+		scnprintf(name, sizeof(name), "powerpc-common-%s-%lld",
+			  psname, id);
 		break;
 	case PSTORE_TYPE_UNKNOWN:
-		sprintf(name, "unknown-%s-%lld", psname, id);
+		scnprintf(name, sizeof(name), "unknown-%s-%lld", psname, id);
 		break;
 	default:
-		sprintf(name, "type%d-%s-%lld", type, psname, id);
+		scnprintf(name, sizeof(name), "type%d-%s-%lld",
+			  type, psname, id);
 		break;
 	}