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
.