ui/clipboard: add asserts for update and request

Should an issue like CVE-2023-6683 ever appear again in the future,
it will be more obvious which assumption was violated.

Suggested-by: Marc-André

ui/clipboard: add asserts for update and request

Should an issue like CVE-2023-6683 ever appear again in the future,
it will be more obvious which assumption was violated.

Suggested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <20240124105749.204610-2-f.ebner@proxmox.com>

show more ...

ui/clipboard: mark type as not available when there is no data

With VNC, a client can send a non-extended VNC_MSG_CLIENT_CUT_TEXT
message with len=0. In qemu_clipboard_set_data(), the clipboard info

ui/clipboard: mark type as not available when there is no data

With VNC, a client can send a non-extended VNC_MSG_CLIENT_CUT_TEXT
message with len=0. In qemu_clipboard_set_data(), the clipboard info
will be updated setting data to NULL (because g_memdup(data, size)
returns NULL when size is 0). If the client does not set the
VNC_ENCODING_CLIPBOARD_EXT feature when setting up the encodings, then
the 'request' callback for the clipboard peer is not initialized.
Later, because data is NULL, qemu_clipboard_request() can be reached
via vdagent_chr_write() and vdagent_clipboard_recv_request() and
there, the clipboard owner's 'request' callback will be attempted to
be called, but that is a NULL pointer.

In particular, this can happen when using the KRDC (22.12.3) VNC
client.

Another scenario leading to the same issue is with two clients (say
noVNC and KRDC):

The noVNC client sets the extension VNC_FEATURE_CLIPBOARD_EXT and
initializes its cbpeer.

The KRDC client does not, but triggers a vnc_client_cut_text() (note
it's not the _ext variant)). There, a new clipboard info with it as
the 'owner' is created and via qemu_clipboard_set_data() is called,
which in turn calls qemu_clipboard_update() with that info.

In qemu_clipboard_update(), the notifier for the noVNC client will be
called, i.e. vnc_clipboard_notify() and also set vs->cbinfo for the
noVNC client. The 'owner' in that clipboard info is the clipboard peer
for the KRDC client, which did not initialize the 'request' function.
That sounds correct to me, it is the owner of that clipboard info.

Then when noVNC sends a VNC_MSG_CLIENT_CUT_TEXT message (it did set
the VNC_FEATURE_CLIPBOARD_EXT feature correctly, so a check for it
passes), that clipboard info is passed to qemu_clipboard_request() and
the original segfault still happens.

Fix the issue by handling updates with size 0 differently. In
particular, mark in the clipboard info that the type is not available.

While at it, switch to g_memdup2(), because g_memdup() is deprecated.

Cc: qemu-stable@nongnu.org
Fixes: CVE-2023-6683
Reported-by: Markus Frank <m.frank@proxmox.com>
Suggested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Markus Frank <m.frank@proxmox.com>
Message-ID: <20240124105749.204610-1-f.ebner@proxmox.com>

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ui/clipboard: reset the serial state on reset

Not only we have to reset the vdagent clipboards serial state, but also
the current QEMU clipboards info serial (the value is currently used by
qemu_cli

ui/clipboard: reset the serial state on reset

Not only we have to reset the vdagent clipboards serial state, but also
the current QEMU clipboards info serial (the value is currently used by
qemu_clipboard_check_serial, only used by -display dbus).

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-5-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: fix serial priority

The incoming grab event should have a higher serial.
See also "vdagent: introduce VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL":
https://gitlab.freedesktop.org/spice/spice-pr

ui/clipboard: fix serial priority

The incoming grab event should have a higher serial.
See also "vdagent: introduce VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL":
https://gitlab.freedesktop.org/spice/spice-protocol/-/commit/045a6978d6dbbf7046affc5c321fa8177c8cce56

This is only a relevant fix for the -display dbus, only user of that
function.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-3-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui: add some vdagent related traces

This helps debugging clipboard serial sync issues.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-2-marcandre.

ui: add some vdagent related traces

This helps debugging clipboard serial sync issues.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-2-marcandre.lureau@redhat.com>

[ kraxel: code style fix ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: reset the serial state on reset

Not only we have to reset the vdagent clipboards serial state, but also
the current QEMU clipboards info serial (the value is currently used by
qemu_cli

ui/clipboard: reset the serial state on reset

Not only we have to reset the vdagent clipboards serial state, but also
the current QEMU clipboards info serial (the value is currently used by
qemu_clipboard_check_serial, only used by -display dbus).

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-5-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: fix serial priority

The incoming grab event should have a higher serial.
See also "vdagent: introduce VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL":
https://gitlab.freedesktop.org/spice/spice-pr

ui/clipboard: fix serial priority

The incoming grab event should have a higher serial.
See also "vdagent: introduce VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL":
https://gitlab.freedesktop.org/spice/spice-protocol/-/commit/045a6978d6dbbf7046affc5c321fa8177c8cce56

This is only a relevant fix for the -display dbus, only user of that
function.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-3-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui: add some vdagent related traces

This helps debugging clipboard serial sync issues.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-2-marcandre.

ui: add some vdagent related traces

This helps debugging clipboard serial sync issues.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-2-marcandre.lureau@redhat.com>

[ kraxel: code style fix ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: reset the serial state on reset

Not only we have to reset the vdagent clipboards serial state, but also
the current QEMU clipboards info serial (the value is currently used by
qemu_cli

ui/clipboard: reset the serial state on reset

Not only we have to reset the vdagent clipboards serial state, but also
the current QEMU clipboards info serial (the value is currently used by
qemu_clipboard_check_serial, only used by -display dbus).

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-5-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: fix serial priority

The incoming grab event should have a higher serial.
See also "vdagent: introduce VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL":
https://gitlab.freedesktop.org/spice/spice-pr

ui/clipboard: fix serial priority

The incoming grab event should have a higher serial.
See also "vdagent: introduce VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL":
https://gitlab.freedesktop.org/spice/spice-protocol/-/commit/045a6978d6dbbf7046affc5c321fa8177c8cce56

This is only a relevant fix for the -display dbus, only user of that
function.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-3-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui: add some vdagent related traces

This helps debugging clipboard serial sync issues.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-2-marcandre.

ui: add some vdagent related traces

This helps debugging clipboard serial sync issues.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-2-marcandre.lureau@redhat.com>

[ kraxel: code style fix ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: reset the serial state on reset

Not only we have to reset the vdagent clipboards serial state, but also
the current QEMU clipboards info serial (the value is currently used by
qemu_cli

ui/clipboard: reset the serial state on reset

Not only we have to reset the vdagent clipboards serial state, but also
the current QEMU clipboards info serial (the value is currently used by
qemu_clipboard_check_serial, only used by -display dbus).

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-5-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: fix serial priority

The incoming grab event should have a higher serial.
See also "vdagent: introduce VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL":
https://gitlab.freedesktop.org/spice/spice-pr

ui/clipboard: fix serial priority

The incoming grab event should have a higher serial.
See also "vdagent: introduce VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL":
https://gitlab.freedesktop.org/spice/spice-protocol/-/commit/045a6978d6dbbf7046affc5c321fa8177c8cce56

This is only a relevant fix for the -display dbus, only user of that
function.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-3-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui: add some vdagent related traces

This helps debugging clipboard serial sync issues.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-2-marcandre.

ui: add some vdagent related traces

This helps debugging clipboard serial sync issues.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-2-marcandre.lureau@redhat.com>

[ kraxel: code style fix ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: reset the serial state on reset

Not only we have to reset the vdagent clipboards serial state, but also
the current QEMU clipboards info serial (the value is currently used by
qemu_cli

ui/clipboard: reset the serial state on reset

Not only we have to reset the vdagent clipboards serial state, but also
the current QEMU clipboards info serial (the value is currently used by
qemu_clipboard_check_serial, only used by -display dbus).

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-5-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: fix serial priority

The incoming grab event should have a higher serial.
See also "vdagent: introduce VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL":
https://gitlab.freedesktop.org/spice/spice-pr

ui/clipboard: fix serial priority

The incoming grab event should have a higher serial.
See also "vdagent: introduce VD_AGENT_CAP_CLIPBOARD_GRAB_SERIAL":
https://gitlab.freedesktop.org/spice/spice-protocol/-/commit/045a6978d6dbbf7046affc5c321fa8177c8cce56

This is only a relevant fix for the -display dbus, only user of that
function.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-3-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui: add some vdagent related traces

This helps debugging clipboard serial sync issues.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-2-marcandre.

ui: add some vdagent related traces

This helps debugging clipboard serial sync issues.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220912102455.111765-2-marcandre.lureau@redhat.com>

[ kraxel: code style fix ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: fix use-after-free regression

The same info may be used to update the clipboard, and may be freed
before being ref'ed again.

Fixes: 70a54b01693ed ("ui: avoid compiler warnings from un

ui/clipboard: fix use-after-free regression

The same info may be used to update the clipboard, and may be freed
before being ref'ed again.

Fixes: 70a54b01693ed ("ui: avoid compiler warnings from unused clipboard info variable")

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220214115917.1679568-1-marcandre.lureau@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

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ui: avoid compiler warnings from unused clipboard info variable

With latest clang 13.0.0 we get

../ui/clipboard.c:47:34: error: variable 'old' set but not used [-Werror,-Wunused-but-set-variable]

ui: avoid compiler warnings from unused clipboard info variable

With latest clang 13.0.0 we get

../ui/clipboard.c:47:34: error: variable 'old' set but not used [-Werror,-Wunused-but-set-variable]
g_autoptr(QemuClipboardInfo) old = NULL;
^

The compiler can't tell that we only declared this variable in
order to get the side effect of free'ing it when out of scope.

This pattern is a little dubious for a use of g_autoptr, so
rewrite the code to avoid it.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
[AJB: fix merge conflict]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20211215141949.3512719-2-berrange@redhat.com>
Message-Id: <20220105135009.1584676-2-alex.bennee@linaro.org>

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ui/clipboard: add a clipboard reset serial event

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

ui/clipboard: add qemu_clipboard_check_serial()

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

ui: generalize clipboard notifier

Use a QemuClipboardNotify union type for extendable clipboard events.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxe

ui: generalize clipboard notifier

Use a QemuClipboardNotify union type for extendable clipboard events.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: release owned grabs on unregister

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210805135715.857938-9-marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffma

ui/clipboard: release owned grabs on unregister

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210805135715.857938-9-marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: add qemu_clipboard_peer_release() helper

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210805135715.857938-8-marcandre.lureau@redhat.com>
Acked-by: Gerd

ui/clipboard: add qemu_clipboard_peer_release() helper

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210805135715.857938-8-marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...

ui/clipboard: add qemu_clipboard_peer_owns() helper

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210805135715.857938-7-marcandre.lureau@redhat.com>
Acked-by: Gerd Ho

ui/clipboard: add qemu_clipboard_peer_owns() helper

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210805135715.857938-7-marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

show more ...