Check destination buffer size on read()

tillitis · Jan 22, 2024 · d24c95d · d24c95d
1 parent 9300507
commit d24c95d
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/include/tkey/proto.h b/include/tkey/proto.h
@@ -39,6 +39,5 @@ int parseframe(uint8_t b, struct frame_header *hdr);
 void writebyte(uint8_t b);
 void write(const uint8_t *buf, size_t nbytes);
 uint8_t readbyte();
-void read(uint8_t *buf, size_t nbytes);
-
+int read(uint8_t *buf, size_t bufsize, size_t nbytes);
 #endif
diff --git a/libcommon/proto.c b/libcommon/proto.c
@@ -82,9 +82,15 @@ uint8_t readbyte()
 	}
 }
 
-void read(uint8_t *buf, size_t nbytes)
+int read(uint8_t *buf, size_t bufsize, size_t nbytes)
 {
+	if (nbytes > bufsize) {
+		return -1;
+	}
+
 	for (int n = 0; n < nbytes; n++) {
 		buf[n] = readbyte();
 	}
+
+	return 0;
 }