2022-08-28 20:58:29

by Li Zhong

Subject: [PATCH v1] drivers/acpi/processor_idle: check the return value of acpi_fetch_acpi_dev()

The return value of acpi_fetch_acpi_dev() could be NULL, which will
cause null pointer dereference if used in acpi_device_hid().

Signed-off-by: Li Zhong <[email protected]>
---
drivers/acpi/processor_idle.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 16a1663d02d4..519f8f741da3 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -1117,6 +1117,8 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
status = acpi_get_parent(handle, &pr_ahandle);
while (ACPI_SUCCESS(status)) {
d = acpi_fetch_acpi_dev(pr_ahandle);
+ if (!d)
+ break;
handle = pr_ahandle;

if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
--
2.25.1

2022-08-29 14:55:15

by Rafael J. Wysocki

Subject: Re: [PATCH v1] drivers/acpi/processor_idle: check the return value of acpi_fetch_acpi_dev()

On Sun, Aug 28, 2022 at 10:54 PM Li Zhong <[email protected]> wrote:
>
> The return value of acpi_fetch_acpi_dev() could be NULL, which will
> cause null pointer dereference if used in acpi_device_hid().

That's true.

> Signed-off-by: Li Zhong <[email protected]>
> ---
> drivers/acpi/processor_idle.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 16a1663d02d4..519f8f741da3 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -1117,6 +1117,8 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
> status = acpi_get_parent(handle, &pr_ahandle);
> while (ACPI_SUCCESS(status)) {
> d = acpi_fetch_acpi_dev(pr_ahandle);
> + if (!d)
> + break;

But shouldn't this be continue?

> handle = pr_ahandle;
>
> if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
> --
> 2.25.1
>

2022-09-03 23:30:08

by Li Zhong

Subject: Re: [PATCH v1] drivers/acpi/processor_idle: check the return value of acpi_fetch_acpi_dev()

On Mon, Aug 29, 2022 at 6:56 AM Rafael J. Wysocki <[email protected]> wrote:
>
> On Sun, Aug 28, 2022 at 10:54 PM Li Zhong <[email protected]> wrote:
> >
> > The return value of acpi_fetch_acpi_dev() could be NULL, which will
> > cause null pointer dereference if used in acpi_device_hid().
>
> That's true.
>
> > Signed-off-by: Li Zhong <[email protected]>
> > ---
> > drivers/acpi/processor_idle.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> > index 16a1663d02d4..519f8f741da3 100644
> > --- a/drivers/acpi/processor_idle.c
> > +++ b/drivers/acpi/processor_idle.c
> > @@ -1117,6 +1117,8 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
> > status = acpi_get_parent(handle, &pr_ahandle);
> > while (ACPI_SUCCESS(status)) {
> > d = acpi_fetch_acpi_dev(pr_ahandle);
> > + if (!d)
> > + break;
>
> But shouldn't this be continue?
>

I think here is break instead of continue because if we use continue, variable
status will not change. Then the while condition will stay true and loop
forever.

> > handle = pr_ahandle;
> >
> > if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
> > --
> > 2.25.1
> >

2022-09-10 16:43:43

by Rafael J. Wysocki

Subject: Re: [PATCH v1] drivers/acpi/processor_idle: check the return value of acpi_fetch_acpi_dev()

On Sun, Aug 28, 2022 at 10:54 PM Li Zhong <[email protected]> wrote:
>
> The return value of acpi_fetch_acpi_dev() could be NULL, which will
> cause null pointer dereference if used in acpi_device_hid().
>
> Signed-off-by: Li Zhong <[email protected]>
> ---
> drivers/acpi/processor_idle.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 16a1663d02d4..519f8f741da3 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -1117,6 +1117,8 @@ static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
> status = acpi_get_parent(handle, &pr_ahandle);
> while (ACPI_SUCCESS(status)) {
> d = acpi_fetch_acpi_dev(pr_ahandle);
> + if (!d)
> + break;
> handle = pr_ahandle;
>
> if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
> --

Applied (with some edits in the subject and changelog) as 6.1 material, thanks!