2054415 - [wayland] Proper wl_fixes version with older host libwayland

Status: RESOLVED FIXED

(Core :: Widget: Gtk, defect)

Description

[Vlad Zahorodnii [:zzag]]

Follow up from https://bugzilla.mozilla.org/show_bug.cgi?id=2044559.

If the host libwayland-client is old (< 1.26), but the compositor announces support for wl_fixes v2, FF can bind wl_fixes v2 even though it shouldn't. If both FF and compositor use the same libwayland, this shouldn't happen, but if the compositor uses a different wayland implementation library, it may.

It should be possible to address the issue by checking wl_interface::version before attempting to bind the wl_fixes global.

Comment 1

[Vlad Zahorodnii [:zzag]]

Attachment: Bug 2054415 - Fix wl_fixes version, r=stransky

If the compositor announces the wl_fixes global with a version 2, the
loaded wl_fixes_interface can still have version 1. For example, such a
case may arise if the host libwayland has a version < 1.26, while the
compositor uses a different libwayland implementation.

If we use MIN(version, 2) and wl_fixes_interface->version is 1, then it
is possible to have a read out of bounds when calling
wl_fixes::ack_global_remove().

In order to prevent that, this change adds an additional check: we also
check that the loaded wl_fixes_interface has the right version.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/a8e2b4c7f4c0
https://hg.mozilla.org/integration/autoland/rev/7630cafc691f
Fix wl_fixes version, r=stransky

Comment 3

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/7630cafc691f