[PATCH v2 0/3] Deal with destroy signal use after free issues

Derek Foreman derekf at osg.samsung.com
Mon Apr 16 20:00:57 UTC 2018

Now that the release is out, I'd like to dig back into this mess.
This is a round up of some patches that were on list shortly before
the release to deal with a problem where many existing libwayland
users don't delete their destroy signal listeners before freeing

These leads to a bit of a mess (as Markus' test illustrates) if there
are multiple destroy listeners.

I've included:
My test patch to ensure the existing behaviour continues to work
(users like weston and enlightenment can free during destroy

The special case destroy emit path for wl_priv_signal - this is
an attempt to "fix" the problem, by making the destroy signal
emit operate without ever touching potentially free()d elements

Markus' test that would fail without patch 2/3, as it catches the
free() without removal case we've all come to know any love.

Derek Foreman (2):
  tests: Test for use after free in resource destruction signals
   changes since first appearance: none

  server: Add special case destroy signal emitter
   changes since first appearance:  stop trying to maintain a list head

Markus Ongyerth (1):
  tests: Add free-without-remove test
   changes since first appearance: I moved it into an existing file

 src/wayland-private.h  |  3 +++
 src/wayland-server.c   | 46 +++++++++++++++++++++++++++++++++++++++++++---
 tests/resources-test.c | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 85 insertions(+), 3 deletions(-)


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