Re: [PATCH] ACPI: configfs: add missing check after configfs_register_default_group

[Hanjun Guo]

On 2021/1/13 15:30, Qinglang Miao wrote:

A list_add corruption is reported by Hulk Robot like this:
==============
list_add corruption.
Call Trace:
link_obj+0xc0/0x1c0
link_group+0x21/0x140
configfs_register_subsystem+0xdb/0x380
acpi_configfs_init+0x25/0x1000 [acpi_configfs]
do_one_initcall+0x149/0x820
do_init_module+0x1ef/0x720
load_module+0x35c8/0x4380
__do_sys_finit_module+0x10d/0x1a0
do_syscall_64+0x34/0x80

It's because of the missing check after configfs_register_default_group,
where configfs_unregister_subsystem should be called once failure.

I think it's right to call *_unregister_* for error path, but...

Fixes: 612bd01fc6e0 ("ACPI: add support for loading SSDTs via configfs")
Reported-by: Hulk Robot <hul...@huawei.com>
Signed-off-by: Qinglang Miao <miaoqingl...@huawei.com>
---
  drivers/acpi/acpi_configfs.c | 7 ++++++-
  1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/acpi_configfs.c b/drivers/acpi/acpi_configfs.c
index cf91f4910..25512ab0e 100644
--- a/drivers/acpi/acpi_configfs.c
+++ b/drivers/acpi/acpi_configfs.c
@@ -268,7 +268,12 @@ static int __init acpi_configfs_init(void)

acpi_table_group = configfs_register_default_group(root, "table",

                                                           &acpi_tables_type);
-       return PTR_ERR_OR_ZERO(acpi_table_group);
+       if (IS_ERR(acpi_table_group)) {
+               configfs_register_subsystem(&acpi_configfs);

...

Typo here, s/register/unregister.

Thanks
Hanjun