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platform/surface: acpi-notify: Check ACPI companion before use

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Since 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(),
platform drivers that rely on the existence of a device's ACPI companion
object should verify its presence.

san_probe() dereferences the result of ACPI_COMPANION() when installing
the GSBUS address space handler, so force-binding the driver to a device
without an ACPI companion leads to a NULL pointer dereference.  The
dereference was introduced when the probe function was switched from
ACPI_HANDLE() to ACPI_COMPANION().

Check the ACPI companion against NULL and return -ENODEV when it is
missing, like commit e4865a56d0 ("ACPI: driver: Check ACPI_COMPANION()
against NULL during probe") does for the core ACPI platform drivers.

Fixes: a9e10e5873 ("ACPI: scan: Extend acpi_walk_dep_device_list()")
Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
Link: https://patch.msgid.link/20260706012512.524359-2-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 09:25:11 +08:00
committed by Ilpo Järvinen
parent c38cce70ad
commit 2b3a5dabe8
1 changed files with 5 additions and 1 deletions
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6
drivers/platform/surface/surface_acpi_notify.c
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@@ -777,12 +777,16 @@ static int san_consumer_links_setup(struct platform_device *pdev)
static int san_probe(struct platform_device *pdev)
{
struct acpi_device *san = ACPI_COMPANION(&pdev->dev);
struct ssam_controller *ctrl;
struct acpi_device *san;
struct san_data *data;
acpi_status astatus;
int status;
san = ACPI_COMPANION(&pdev->dev);
if (!san)
return -ENODEV;
ctrl = ssam_client_bind(&pdev->dev);
if (IS_ERR(ctrl))
return PTR_ERR(ctrl) == -ENODEV ? -EPROBE_DEFER : PTR_ERR(ctrl);