[syslog-ng] [PATCH (3.4)] affile: Fix NULL dereference when opening the destination fails.

[Gergely Nagy]

Viktor Tusa discovered an error in the affile destination driver: if
opening the destination failed (for example, due to insufficient
permissions), next was set to NULL, and later on, at the end of
affile_dd_open_writer() tried to dereferrence it.

A simple workaround is to return NULL in case next is NULL.

Reported-by: Viktor Tusa <tusa at balabit.hu>
Signed-off-by: Gergely Nagy <algernon at balabit.hu>
---
 modules/affile/affile.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/modules/affile/affile.c b/modules/affile/affile.c
index 87767aa..57ccb7a 100644
--- a/modules/affile/affile.c
+++ b/modules/affile/affile.c
@@ -1052,6 +1052,9 @@ affile_dd_open_writer(gpointer args[])
             }
 	}
     }
+  if (!next)
+    return NULL;
+
   next->queue_pending = TRUE;
   /* we're returning a reference */
   return &next->super;
-- 
1.7.2.5