From 6b5eab54691956b27669ce726cbd8ef2d8ec1e50 Mon Sep 17 00:00:00 2001 From: Chris Bainbridge Date: Wed, 22 Apr 2015 00:25:36 +0100 Subject: [PATCH] ACPI / EC: fix NULL pointer dereference in acpi_ec_remove_query_handler() Use list_for_each_entry_safe for iterating because handler may be freed in the loop. BUG: unable to handle kernel NULL pointer dereference at 000000000000002c IP: [] acpi_ec_put_query_handler+0x7/0x1a Call Trace: acpi_ec_remove_query_handler+0x87/0x97 acpi_smbus_hc_remove+0x2a/0x44 [sbshc] acpi_device_remove+0x7b/0x9a __device_release_driver+0x7e/0x110 driver_detach+0xb0/0xc0 bus_remove_driver+0x54/0xe0 driver_unregister+0x2b/0x60 acpi_bus_unregister_driver+0x10/0x12 acpi_smb_hc_driver_exit+0x10/0x12 [sbshc] SyS_delete_module+0x1b8/0x210 system_call_fastpath+0x12/0x6a Signed-off-by: Chris Bainbridge Signed-off-by: Rafael J. Wysocki --- drivers/acpi/ec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 220d6406c9e9..5e8fed448850 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -861,7 +861,7 @@ void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit) } } mutex_unlock(&ec->mutex); - list_for_each_entry(handler, &free_list, node) + list_for_each_entry_safe(handler, tmp, &free_list, node) acpi_ec_put_query_handler(handler); } EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler);