We need to prevent infinite loops and lockups
Signed-off-by: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
---
drivers/acpi/dispatcher/dsopcode.c | 9 +++++++--
include/acpi/acstruct.h | 1 +
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/dispatcher/dsopcode.c b/drivers/acpi/dispatcher/dsopcode.c
index 6a81c44..e2a3535 100644
--- a/drivers/acpi/dispatcher/dsopcode.c
+++ b/drivers/acpi/dispatcher/dsopcode.c
@@ -1246,8 +1246,13 @@ acpi_ds_exec_end_control_op(struct acpi_walk_state * walk_state,
if (walk_state->control_state->common.value) {
/* Predicate was true, go back and evaluate it again! */
-
- status = AE_CTRL_PENDING;
+ /* Use hard limit to prevent infinite loops and lockups */
+ if (++walk_state->cycle_count > 0xFFFF) {
+ status = AE_LIMIT;
+ ACPI_ERROR ((AE_INFO, "Infinite loop detected"));
+ } else {
+ status = AE_CTRL_PENDING;
+ }
}
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
diff --git a/include/acpi/acstruct.h b/include/acpi/acstruct.h
index 7980a26..fb4405e 100644
--- a/include/acpi/acstruct.h
+++ b/include/acpi/acstruct.h
@@ -94,6 +94,7 @@ struct acpi_walk_state {
u32 method_breakpoint; /* For single stepping */
u32 user_breakpoint; /* User AML breakpoint */
u32 parse_flags;
+ u32 cycle_count; /* While loop cycle count */
struct acpi_parse_state parser_state; /* Current state of parser */
u32 prev_arg_types;
--
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