On Sat, Jan 26, 2019 at 05:14:54PM +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 io_cleanup() while try_smi_init() goes to out_err
> 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@xxxxxxxxxxxxxxx
> Reported-by: NuoHan Qiao <qiaonuohan@xxxxxxxxxx>
> Suggested-by: Corey Minyard <cminyard@xxxxxxxxxx>
> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> ---
> drivers/char/ipmi/ipmi_si_intf.c | 5 +++++
> drivers/char/ipmi/ipmi_si_port_io.c | 3 +++
> 2 files changed, 8 insertions(+)
>
> diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
> index dc8603d..f1b9fda 100644
> --- a/drivers/char/ipmi/ipmi_si_intf.c
> +++ b/drivers/char/ipmi/ipmi_si_intf.c
> @@ -2085,6 +2085,11 @@ static int try_smi_init(struct smi_info *new_smi)
> WARN_ON(new_smi->io.dev->init_name != NULL);
>
> out_err:
> + if (rv && new_smi->io.io_cleanup) {
> + new_smi->io.io_cleanup(&new_smi->io);
> + new_smi->io.io_cleanup = NULL;
> + }
> +
> kfree(init_name);
> return rv;
> }
> 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;
> +
Why do you need this part? I can't see the reason for it. The addr
part below should handle that, especially with the above change.
-corey
> if (addr) {
> for (idx = 0; idx < io->io_size; idx++)
> release_region(addr + idx * io->regspacing,
> --
> 1.8.3
>
>
>
>
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