From 700641afb86c7615377fa78b5df448ffaaa50c0f Mon Sep 17 00:00:00 2001
From: Thomas Veerman <thomas@minix3.org>
Date: Mon, 16 Jan 2012 15:09:55 +0000
Subject: [PATCH] lseek should not yield a negative file position

---
 servers/avfs/open.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/servers/avfs/open.c b/servers/avfs/open.c
index a236107fd..e3cbf4470 100644
--- a/servers/avfs/open.c
+++ b/servers/avfs/open.c
@@ -612,9 +612,11 @@ PUBLIC int do_lseek()
 	newpos = sub64ul(pos, -offset);
 
   /* Check for overflow. */
-  if (ex64hi(newpos) != 0)
-	r = EINVAL;
-  else {
+  if (ex64hi(newpos) != 0) {
+	r = EOVERFLOW;
+  } else if ((off_t) ex64lo(newpos) < 0) { /* no negative file size */
+	r = EOVERFLOW;
+  } else {
 	rfilp->filp_pos = newpos;
 
 	/* insert the new position into the output message */
-- 
2.44.0