On Tue, Nov 15, 2022 at 04:17:43PM +0300, Dan Carpenter wrote:
> The intf_free() function frees the "intf" pointer so we cannot
> dereference it again on the next line.
Thanks. I will request a backport for 5.5 and later.
>
> Fixes: cbb79863fc31 ("ipmi: Don't allow device module unload when in use")
> Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
> ---
> drivers/char/ipmi/ipmi_msghandler.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index f6b8ca6df9b5..186f1fee7534 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -1330,6 +1330,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
> unsigned long flags;
> struct cmd_rcvr *rcvr;
> struct cmd_rcvr *rcvrs = NULL;
> + struct module *owner;
>
> if (!acquire_ipmi_user(user, &i)) {
> /*
> @@ -1392,8 +1393,9 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
> kfree(rcvr);
> }
>
> + owner = intf->owner;
> kref_put(&intf->refcount, intf_free);
> - module_put(intf->owner);
> + module_put(owner);
> }
>
> int ipmi_destroy_user(struct ipmi_user *user)
> --
> 2.35.1
>
