spmi: Fix potential use-after-free by grabbing of_node reference

As noticed by Sashiko during a review run of an unrelated patch,
in of_spmi_register_devices(), for_each_available_child_of_node()
is used to loop through children, and to also assign a node to a
newly created SPMI child device.

Problem is that the refcount is dropped at every iteration so, in
the specific case of DT overlays, a use-after-free may occur when
an overlay is dynamically unloaded!

To resolve this, increase the of_node refcount when assigning (in
function of_spmi_register_devices) and release the reference in
spmi_device_remove().

Fixes: bc32bbd04011 ("spmi: Set fwnode for spmi devices")
Cc: stable@vger.kernel.org
Reported-by: Sashiko Bot <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260608100949.36309-1-angelogioacchino.delregno@collabora.com?part=2
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

0 files changed, 0 insertions, 0 deletions