[PATCH v2] PCI/ACPI: Check the found handle in acpi_get_rc_resources()

[PATCH v2] PCI/ACPI: Check the found handle in acpi_get_rc_resources()

[lirongqing]

From: Li RongQing <lirongqing@baidu.com>

acpi_get_devices() returns AE_OK even when the namespace walk finishes
without a match, in which case the return_value argument is not written.
The caller passes an uninitialized acpi_handle and hands it to
acpi_fetch_acpi_dev(), which dereferences it as an ACPI node.

Initialize the handle and reject a missing match.

Fixes: 169de969c018 ("PCI/ACPI: Provide acpi_get_rc_resources() for ARM64 platform")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
---
Diff with v1: add fixes tag

 drivers/pci/pci-acpi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index e260089..e90e749 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -82,7 +82,7 @@ int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment,
 {
 	struct acpi_device *adev;
 	acpi_status status;
-	acpi_handle handle;
+	acpi_handle handle = NULL;
 	int ret;
 
 	status = acpi_get_devices(hid, acpi_match_rc, &segment, &handle);
@@ -92,6 +92,9 @@ int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment,
 		return -ENODEV;
 	}
 
+	if (!handle)
+		return -ENODEV;
+
 	adev = acpi_fetch_acpi_dev(handle);
 	if (!adev)
 		return -ENODEV;
-- 
2.9.4

Re: [PATCH v2] PCI/ACPI: Check the found handle in acpi_get_rc_resources()

[sashiko-bot]

> From: Li RongQing <lirongqing@baidu.com>
> 
> acpi_get_devices() returns AE_OK even when the namespace walk finishes
> without a match, in which case the return_value argument is not written.
> The caller passes an uninitialized acpi_handle and hands it to
> acpi_fetch_acpi_dev(), which dereferences it as an ACPI node.
> 
> Initialize the handle and reject a missing match.
> 
> Fixes: 169de969c018 ("PCI/ACPI: Provide acpi_get_rc_resources() for ARM64 platform")
> Signed-off-by: Li RongQing <lirongqing@baidu.com>

Sashiko has reviewed this patch and found no issues.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261115091221.2217-1-lirongqing@baidu.com?part=1