From 53c6f9fb43624e4d48ef3a624dfe9511ef631c0e Mon Sep 17 00:00:00 2001
From: Patrick McDermott <patrick.mcdermott@libiquity.com>
Date: Mon, 17 Apr 2023 10:27:09 -0400
Subject: gzip: Make more robust

---
diff --git a/src/gzip.c b/src/gzip.c
index de733f9..302ba72 100644
--- a/src/gzip.c
+++ b/src/gzip.c
@@ -60,36 +60,49 @@ opkg_opk_gzip_init(opkg_opk_gzip_read_func *read, void *user_data)
 int
 opkg_opk_gzip_read(struct opkg_opk_gzip *gzip, void *record)
 {
+	int end;
+
 	gzip->stream.next_out  = record;
 	gzip->stream.avail_out = OPKG_OPK_USTAR_RECORD_SIZE;
 
 	for (;;) {
+		end = 0;
 		if (gzip->stream.avail_in == 0) {
 			/* Input buffer is empty and needs refilled. */
 			switch (gzip->read(gzip->user_data,
 						&gzip->stream.next_in,
 						&gzip->stream.avail_in)) {
 				case OPKG_OPK_OK:
+					break;
 				case OPKG_OPK_END:
+					end = 1;
 					break;
 				case OPKG_OPK_ERROR:
 				default:
 					return OPKG_OPK_ERROR;
 			}
 		}
-		if (gzip->stream.avail_out == 0) {
-			/* Output buffer is filled and ready for use. */
-			return OPKG_OPK_OK;
-		}
 		switch (inflate(&gzip->stream, Z_SYNC_FLUSH)) {
 			case Z_OK:
+				break;
 			case Z_BUF_ERROR:
+				if (end == 1) {
+					return OPKG_OPK_ERROR;
+				}
 				break;
 			case Z_STREAM_END:
+				if (gzip->stream.avail_out != 0) {
+					/* Premature end */
+					return OPKG_OPK_ERROR;
+				}
 				return OPKG_OPK_END;
 			default:
 				return OPKG_OPK_ERROR;
 		}
+		if (gzip->stream.avail_out == 0) {
+			/* Output buffer is filled and ready for use. */
+			return OPKG_OPK_OK;
+		}
 	}
 }
 
--
cgit v0.9.1