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

[PATCH] 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.

Signed-off-by: Li RongQing <lirongqing@baidu.com>
---
 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] PCI/ACPI: Check the found handle in acpi_get_rc_resources()

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Low] PCI/ACPI: missing Fixes trailer for acpi_get_rc_resources() fix
--

commit 2dd263c8741dc2f24a59dc48d0def98c31872ce2
Author: Li RongQing <lirongqing@baidu.com>

> PCI/ACPI: Check the found handle in acpi_get_rc_resources()
>
> 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.
>
> Signed-off-by: Li RongQing <lirongqing@baidu.com>

[Severity: Low]
Since this fixes an uninitialized handle dereference in
acpi_get_rc_resources() when acpi_get_devices() completes without a
match, please add a Fixes tag:

  Fixes: 169de969c018 ("PCI/ACPI: Provide acpi_get_rc_resources() for ARM64 platform")

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261110053423.2517-1-lirongqing@baidu.com?part=1

答复: [外部邮件] Re: [PATCH] PCI/ACPI: Check the found handle in acpi_get_rc_resources()

[Li,Rongqing]

> -----邮件原件-----
> 发件人: sashiko-bot@kernel.org <sashiko-bot@kernel.org>
> 发送时间: 2026年11月10日 13:41
> 收件人: Li,Rongqing <lirongqing@baidu.com>; linux-pci@vger.kernel.org
> 主题: [外部邮件] Re: [PATCH] PCI/ACPI: Check the found handle in
> acpi_get_rc_resources()
> 
> Thank you for your contribution! Sashiko AI review found 1 potential issue to
> consider:
> - [Low] PCI/ACPI: missing Fixes trailer for acpi_get_rc_resources() fix
> --
> 
> commit 2dd263c8741dc2f24a59dc48d0def98c31872ce2
> Author: Li RongQing <lirongqing@baidu.com>
> 
> > PCI/ACPI: Check the found handle in acpi_get_rc_resources()
> >
> > 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.
> >
> > Signed-off-by: Li RongQing <lirongqing@baidu.com>
> 
> [Severity: Low]
> Since this fixes an uninitialized handle dereference in
> acpi_get_rc_resources() when acpi_get_devices() completes without a match,
> please add a Fixes tag:
> 
>   Fixes: 169de969c018 ("PCI/ACPI: Provide acpi_get_rc_resources() for ARM64
> platform")
> 

I think this issue has limited impact, so I didn't add a Fixes tag. Please, maintainer, check whether a Fixes tag is needed when merging.

[Li,Rongqing] 

> --
> Sashiko AI
> review · https://sashiko.dev/#/patchset/20261110053423.2517-1-lirongqing
> @baidu.com?part=1

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

[Rafael J. Wysocki (Intel)]

On Tue, Nov 10, 2026 at 6:34 AM lirongqing <lirongqing@baidu.com> wrote:
>
> 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.
>
> Signed-off-by: Li RongQing <lirongqing@baidu.com>

Stable may want to pick up this one, so please add a Fixes: tag as
suggested by Sashiko:

https://sashiko.dev/#/patchset/20261110053423.2517-1-lirongqing%40baidu.com

> ---
>  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;
> --