Hi,
On 2022/11/6 3:00, Rafael J. Wysocki wrote:
On Fri, Oct 28, 2022 at 5:46 PM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
On Wed, Oct 19, 2022 at 9:38 AM Chen Zhongjin <chenzhongjin@xxxxxxxxxx> wrote:
KASAN reports a use-after-free problem and causes kernel panic
triggered by: modprobe acpiphp_ibm
BUG: KASAN:
use-after-free in acpi_ds_dump_method_stack (drivers/acpi/acpica/dsdebug.c:145)
Read of size 8 at addr ffff888002f843f0 by task modprobe/519
CPU: 2 PID: 519 Comm: modprobe Not tainted 6.0.0+
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
<TASK>
acpi_ds_dump_method_stack (drivers/acpi/acpica/dsdebug.c:145)
acpi_ds_method_error (drivers/acpi/acpica/dsmethod.c:232)
acpi_ps_parse_aml (drivers/acpi/acpica/psparse.c:607)
...
</TASK>
Allocated by task 519:
...
__kasan_kmalloc (mm/kasan/common.c:526)
acpi_ds_create_walk_state (drivers/acpi/acpica/dswstate.c:519)
acpi_ds_call_control_method (drivers/acpi/acpica/dsmethod.c:498)
acpi_ps_parse_aml (drivers/acpi/acpica/psparse.c:607)
...
Freed by task 519:
...
__kmem_cache_free+0xb6/0x3c0
acpi_ds_delete_walk_state (drivers/acpi/acpica/dswstate.c:722)
acpi_ds_call_control_method (drivers/acpi/acpica/dsmethod.c:586)
acpi_ps_parse_aml (drivers/acpi/acpica/psparse.c:607)
...
---[ end Kernel panic - not syncing: Fatal exception ]---
In the error path in acpi_ps_parse_aml():
acpi_ds_call_control_method()
acpi_ds_create_walk_state()
acpi_ds_push_walk_state()
# thread->walk_state_list = walk_state
acpi_ds_init_aml_walk # *fail*
goto cleanup:
acpi_ds_delete_walk_state() # ACPI_FREE(walk_state)
acpi_ds_method_error()
acpi_ds_dump_method_stack()
# using freed thread->walk_state_list
Briefly, the walk_state is pushed to thread, and freed without being poped.
Then it is used in acpi_ds_dump_method_stack() and causes use-after-free.
Add acpi_ds_pop_walk_state(thread) to the error path to fix the problem.
Fixes: 0bac4295526c ("ACPICA: Dispatcher: Move stack traversal code to dispatcher")
Signed-off-by: Chen Zhongjin <chenzhongjin@xxxxxxxxxx>
This should be submitted to the upstream project on GitHub, but it
looks bad enough, so I'll take care of this.
Applied as 6.1-rc material, thanks!
---
drivers/acpi/acpica/dsmethod.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/acpi/acpica/dsmethod.c b/drivers/acpi/acpica/dsmethod.c
index ae2e768830bf..19da7fc73186 100644
--- a/drivers/acpi/acpica/dsmethod.c
+++ b/drivers/acpi/acpica/dsmethod.c
@@ -581,6 +581,7 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
acpi_ds_terminate_control_method(obj_desc, next_walk_state);
acpi_ds_delete_walk_state(next_walk_state);
+ acpi_ds_pop_walk_state(thread);
On second thought, though, should it be popped before deleting?
Otherwise it looks like there will be still use-after-free, because
acpi_ds_pop_walk_state() accesses the walk_state at the top of the
queue.
You are right it is wrong and sorry I didn't notice that.
I have reproduced same problem on current tree... Have no idea why I
missed it before.
I noticed that this patch have been on next-tree so I submitted another
one to fix it.
See "ACPICA: Fix pop_walk_state called after walk_state is deleted"
Thanks for your time!
Best,
Chen
Moreover, it is not correct to pop the walk state if next_walk_state
is NULL AFAICS.
I'm dropping this one.
return_ACPI_STATUS(status);
}
--
Bob, this looks correct to me, but I may be missing something in which
case please let me know.
