From fbc895c61cffb41a68d70d1caa4d429d4d0f72f8 Mon Sep 17 00:00:00 2001
From: Michael Shalayeff <mickey@cvs.openbsd.org>
Date: Mon, 25 Jan 1999 19:28:41 +0000
Subject: fix a real bad bug, which consists of return value from read() /*
 oread() */ not being checked for errors/eof or not checked for error value
 (-1), which would result in bad kernels loaded, i/o errors not reported and
 such.

---
 sys/lib/libsa/cread.c | 17 +++++++++++++----
 sys/lib/libz/zlib.h   |  4 ++--
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/sys/lib/libsa/cread.c b/sys/lib/libsa/cread.c
index 2f024440cba..d75c3ec6e38 100644
--- a/sys/lib/libsa/cread.c
+++ b/sys/lib/libsa/cread.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cread.c,v 1.6 1998/09/08 03:33:06 millert Exp $	*/
+/*	$OpenBSD: cread.c,v 1.7 1999/01/25 19:28:38 mickey Exp $	*/
 /*	$NetBSD: cread.c,v 1.2 1997/02/04 18:38:20 thorpej Exp $	*/
 
 /*
@@ -105,7 +105,7 @@ static int get_byte(s)
     if (s->stream.avail_in == 0) {
 	errno = 0;
 	s->stream.avail_in = oread(s->fd, s->inbuf, Z_BUFSIZE);
-	if (s->stream.avail_in == 0) {
+	if (s->stream.avail_in <= 0) {
 	    s->z_eof = 1;
 	    if (errno) s->z_err = Z_ERRNO;
 	    return EOF;
@@ -279,7 +279,16 @@ read(fd, buf, len)
 		s->stream.avail_in  -= n;
 	      }
 	      if (s->stream.avail_out > 0) {
-		s->stream.avail_out -= oread(fd, s->stream.next_out, s->stream.avail_out);
+		int n;
+		n = oread(fd, s->stream.next_out, s->stream.avail_out);
+		if (n <= 0) {
+		  s->z_eof = 1;
+		  if (errno) {
+		    s->z_err = Z_ERRNO;
+		    break;
+		  }
+	        }
+		s->stream.avail_out -= n;
 	      }
 	      len -= s->stream.avail_out;
 	      s->stream.total_in  += (unsigned long)len;
@@ -292,7 +301,7 @@ read(fd, buf, len)
 
 	      errno = 0;
 	      s->stream.avail_in = oread(fd, s->inbuf, Z_BUFSIZE);
-	      if (s->stream.avail_in == 0) {
+	      if (s->stream.avail_in <= 0) {
 		s->z_eof = 1;
 		if (errno) {
 		  s->z_err = Z_ERRNO;
diff --git a/sys/lib/libz/zlib.h b/sys/lib/libz/zlib.h
index 49f56b43bc6..9e231f491e9 100644
--- a/sys/lib/libz/zlib.h
+++ b/sys/lib/libz/zlib.h
@@ -67,11 +67,11 @@ struct internal_state;
 
 typedef struct z_stream_s {
     Bytef    *next_in;  /* next input byte */
-    uInt     avail_in;  /* number of bytes available at next_in */
+    int      avail_in;  /* number of bytes available at next_in */
     uLong    total_in;  /* total nb of input bytes read so far */
 
     Bytef    *next_out; /* next output byte should be put there */
-    uInt     avail_out; /* remaining free space at next_out */
+    int      avail_out; /* remaining free space at next_out */
     uLong    total_out; /* total nb of bytes output so far */
 
     char     *msg;      /* last error message, NULL if no error */
-- 
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