Messages in this thread Patch in this message | | | From | Tong Zhang <> | Subject | [PATCH] ACPICA: proactively check null ptr to avoid API misuse | Date | Tue, 15 Feb 2022 22:26:15 -0800 |
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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.
Signed-off-by: Tong Zhang <ztong0001@gmail.com> --- 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
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