platform/mellanox: mlxbf-pmc: Check ACPI_COMPANION() against NULL

Every platform driver can be forced to match a device that doesn't match
its list of device IDs because of device_match_driver_override(), so
platform drivers that rely on the existence of a device's ACPI companion
object need to verify its presence.

mlxbf_pmc_probe() passes the result of ACPI_COMPANION() to
acpi_device_hid(), which dereferences it, so force-binding the driver to
a device without an ACPI companion leads to a NULL pointer dereference.

Accordingly, add a requisite ACPI_COMPANION() check against NULL to the
mlxbf-pmc driver and return -ENODEV when the companion is missing.

Fixes: 1a218d312e ("platform/mellanox: mlxbf-pmc: Add Mellanox BlueField PMC driver")
Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
Link: https://patch.msgid.link/20260706012056.524096-1-lilinmao@kylinos.cn
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
This commit is contained in:
Linmao Li 2026-07-06 09:20:56 +08:00 • committed by Ilpo Järvinen
commit c38cce70ad
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