On Wed, Feb 16, 2022 at 7:26 AM Tong Zhang <ztong0001@xxxxxxxxx> wrote: > > There are some cases that user use acpi_ns_walk_namespace() without > checking acpi_disable flag. When acpi=off is provided in boot cmdline, > acpi_gbl_root_node is NULL and calling acpi_ns_walk_namespace() will > crash kernel. In order to avoid such misuse, we proactively check null ptr > and return an error when we know ACPI is disabled. The issue should be fixed by this commit in the upstream ACPICA code base: https://github.com/acpica/acpica/commit/b1c3656ef4950098e530be68d4b589584f06cddc > > Signed-off-by: Tong Zhang <ztong0001@xxxxxxxxx> > --- > drivers/acpi/acpica/nswalk.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/acpi/acpica/nswalk.c b/drivers/acpi/acpica/nswalk.c > index 915c2433463d..9ae45db16d86 100644 > --- a/drivers/acpi/acpica/nswalk.c > +++ b/drivers/acpi/acpica/nswalk.c > @@ -171,6 +171,13 @@ acpi_ns_walk_namespace(acpi_object_type type, > start_node = acpi_gbl_root_node; > } > > + /* acpi_gbl_root_node is NULL when acpi=off is provided. > + * We proactively check nulliness here and return an error if user call > + * this function without checking acpi_disabled > + */ > + if (start_node == NULL) > + return_ACPI_STATUS(AE_ERROR); > + > /* Null child means "get first node" */ > > parent_node = start_node; > -- > 2.25.1 >
