From 4ab1af1fa9e945ffdfcc21e4e4dc5980965bd88f Mon Sep 17 00:00:00 2001
From: Francesco Chemolli <kinkie@squid-cache.org>
Date: Fri, 3 Jul 2015 11:38:18 +0200
Subject: [PATCH] Fix CID 740322: unchecked lseek return value in disk.cc

---
 src/disk.cc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/disk.cc b/src/disk.cc
index bd461f712a..a5ee680909 100644
--- a/src/disk.cc
+++ b/src/disk.cc
@@ -421,7 +421,12 @@ diskHandleRead(int fd, void *data)
     {
 #endif
         debugs(6, 3, "diskHandleRead: FD " << fd << " seeking to offset " << ctrl_dat->offset);
-        lseek(fd, ctrl_dat->offset, SEEK_SET);  /* XXX ignore return? */
+        errno = 0;
+        if (lseek(fd, ctrl_dat->offset, SEEK_SET) == -1) {
+            // shouldn't happen, let's detect that
+            debugs(50, DBG_IMPORTANT, "error in seek for fd " << fd << ": " << xstrerror());
+            // XXX handle failures?
+        }
         ++ statCounter.syscalls.disk.seeks;
         F->disk.offset = ctrl_dat->offset;
     }
-- 
2.47.2