From 1fc9b20a7688000fcf4d7fbaa58e415a3cdda961 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 15 Nov 2022 16:17:43 +0300 Subject: [PATCH] ipmi: fix use after free in _ipmi_destroy_user() commit a92ce570c81dc0feaeb12a429b4bc65686d17967 upstream. The intf_free() function frees the "intf" pointer so we cannot dereference it again on the next line. Fixes: cbb79863fc31 ("ipmi: Don't allow device module unload when in use") Signed-off-by: Dan Carpenter Message-Id: Cc: # 5.5+ Signed-off-by: Corey Minyard Signed-off-by: Greg Kroah-Hartman --- 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 d5ee52b..5d403fb 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) -- 2.7.4