Fix a problem in GLib/gio which caused gnome-shell and others to crash.

The problem happened when, for example, a packages was installed/deinstall
that placed a file in ${LOCALBASE}/share/applications.

Thanks to ajacoutot@openbsd.org and mpi@openbsd.org for bringing these
patches to my attention.

Obtained from:	https://bugzilla.gnome.org/show_bug.cgi?id=739424
		https://bugzilla.gnome.org/show_bug.cgi?id=778515
MFH:		2017Q2

1 files changed, 59 insertions, 0 deletions

diff --git a/devel/glib20/files/patch-bug739424 b/devel/glib20/files/patch-bug739424
new file mode 100644
index 000000000000..c5b8d82925b1
--- /dev/null
+++ b/devel/glib20/files/patch-bug739424
@@ -0,0 +1,59 @@
+From 22656f16c29591207c667362e2a42fd348fe8494 Mon Sep 17 00:00:00 2001
+From: Martin Pieuchot <mpi@openbsd.org>
+Date: Fri, 28 Apr 2017 15:06:52 +0200
+Subject: [PATCH] kqueue: fix use-after-free of ``kqueue_sub''.
+
+Since ``kqueue_sub'' are not refcounted it is common to see a thread
+freeing one of them while another thread is manipulating them.  This
+leads to crashs reported in:
+	https://bugzilla.gnome.org/show_bug.cgi?id=739424
+
+To prevent such crash, make sure the threads are holding ``hash_lock''
+when manipulating such items.
+---
+ gio/kqueue/kqueue-helper.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/gio/kqueue/kqueue-helper.c b/gio/kqueue/kqueue-helper.c
+index d4e66cd4d..84b9ef164 100644
+--- gio/kqueue/kqueue-helper.c
++++ gio/kqueue/kqueue-helper.c
+@@ -291,10 +291,10 @@ process_kqueue_notifications (GIOChannel   *gioc,
+ 
+   G_LOCK (hash_lock);
+   sub = (kqueue_sub *) g_hash_table_lookup (subs_hash_table, GINT_TO_POINTER (n.fd));
+-  G_UNLOCK (hash_lock);
+ 
+   if (sub == NULL)
+     {
++      G_UNLOCK (hash_lock);
+       KH_W ("Got a notification for a deleted or non-existing subscription %d",
+              n.fd);
+       return TRUE;
+@@ -336,6 +336,7 @@ process_kqueue_notifications (GIOChannel   *gioc,
+         g_file_monitor_source_handle_event (source, mask, NULL, NULL, NULL, g_get_monotonic_time ());
+     }
+ 
++  G_UNLOCK (hash_lock);
+   return TRUE;
+ }
+ 
+@@ -451,13 +452,14 @@ _kh_start_watching (kqueue_sub *sub)
+ 
+   G_LOCK (hash_lock);
+   g_hash_table_insert (subs_hash_table, GINT_TO_POINTER (sub->fd), sub);
+-  G_UNLOCK (hash_lock);
+ 
+   _kqueue_thread_push_fd (sub->fd);
+   
+   /* Bump the kqueue thread. It will pick up a new sub entry to monitor */
+   if (!_ku_write (kqueue_socket_pair[0], "A", 1))
+     KH_W ("Failed to bump the kqueue thread (add fd, error %d)", errno);
++  G_UNLOCK (hash_lock);
++
+   return TRUE;
+ }
+ 
+-- 
+2.12.2
+