From: Yang Yingliang <yangyingliang@huawei.com>
To: <cminyard@mvista.com>
Cc: <arnd@arndb.de>, <gregkh@linuxfoundation.org>,
<openipmi-developer@lists.sourceforge.net>,
<linux-kernel@vger.kernel.org>, <stable@vger.kernel.org>,
<qiaonuohan@huawei.com>
Subject: Re: [PATCH] ipmi_si: fix use-after-free of resource->name
Date: Sat, 26 Jan 2019 09:41:37 +0800 [thread overview]
Message-ID: <5C4BBAD1.5050207@huawei.com> (raw)
In-Reply-To: <20190125203524.GA20851@minyard.net>
On 2019/1/26 4:35, Corey Minyard wrote:
> On Fri, Jan 25, 2019 at 10:30:59AM +0800, Yang Yingliang wrote:
>> When we excute the following commands, we got oops
>> rmmod ipmi_si
>> cat /proc/ioports
>>
> snip...
>
>> If io_setup is called successful in try_smi_init() but try_smi_init()
>> goes out_err before calling ipmi_register_smi(), so ipmi_unregister_smi()
>> will not be called while removing module. It leads to the resource that
>> allocated in io_setup() can not be freed, but the name(DEVICE_NAME) of
>> resource is freed while removing the module. It causes use-after-free
>> when cat /proc/ioports.
>>
>> Fix this by calling shutdown_smi() while removing the module and don't
>> call release_region() if request_region() is not called to avoid error
>> prints.
>>
>> Fixes: 93c303d2045b ("ipmi_si: Clean up shutdown a bit")
>> Cc: stable@vger.kernel.org
>> Reported-by: NuoHan Qiao <qiaonuohan@huawei.com>
>> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
>> ---
>> drivers/char/ipmi/ipmi_si_intf.c | 2 ++
>> drivers/char/ipmi/ipmi_si_port_io.c | 3 +++
>> 2 files changed, 5 insertions(+)
>>
>> diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
>> index dc8603d..635e98a 100644
>> --- a/drivers/char/ipmi/ipmi_si_intf.c
>> +++ b/drivers/char/ipmi/ipmi_si_intf.c
>> @@ -2235,6 +2235,8 @@ static void cleanup_one_si(struct smi_info *smi_info)
>>
>> if (smi_info->intf)
>> ipmi_unregister_smi(smi_info->intf);
>> + else
>> + shutdown_smi(smi_info);
> This is completely the wrong way to fix this. The general principle is
> that a function cleans up for itself if it returns an error. If you
> add hacks other places for a function failing you end up with a mess.
>
> I think the right way to fix this is to add something like:
>
> if (rv && new_smi->io.io_size && smi_info->io.io_cleanup) {
> smi_info->io.io_cleanup(&smi_info->io);
> smi_info->io.io_cleanup = NULL;
> }
>
> at the end of try_smi_init().
>
> -corey
OK, I will do some test, and send v2 later.
Thanks,
Yang
>>
>> if (smi_info->pdev) {
>> if (smi_info->pdev_registered)
>> diff --git a/drivers/char/ipmi/ipmi_si_port_io.c b/drivers/char/ipmi/ipmi_si_port_io.c
>> index ef6dffc..0c46a3f 100644
>> --- a/drivers/char/ipmi/ipmi_si_port_io.c
>> +++ b/drivers/char/ipmi/ipmi_si_port_io.c
>> @@ -53,6 +53,9 @@ static void port_cleanup(struct si_sm_io *io)
>> unsigned int addr = io->addr_data;
>> int idx;
>>
>> + if (io->regsize != 1 && io->regsize != 2 && io->regsize != 4)
>> + return;
>> +
>> if (addr) {
>> for (idx = 0; idx < io->io_size; idx++)
>> release_region(addr + idx * io->regspacing,
>> --
>> 1.8.3
>>
>>
> .
>
prev parent reply other threads:[~2019-01-26 1:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-25 2:30 [PATCH] ipmi_si: fix use-after-free of resource->name Yang Yingliang
2019-01-25 20:35 ` Corey Minyard
2019-01-26 1:41 ` Yang Yingliang [this message]
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