tpm: tpm_vtpm_proxy: fix a race condition in /dev/vtpmx creation

commit f4032d615f upstream.

/dev/vtpmx is made visible before 'workqueue' is initialized, which can
lead to a memory corruption in the worst case scenario.

Address this by initializing 'workqueue' as the very first step of the
driver initialization.

Cc: stable@vger.kernel.org
Fixes: 6f99612e25 ("tpm: Proxy driver for supporting multiple emulated TPMs")
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@tuni.fi>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jarkko Sakkinen 2023-05-16 01:25:54 +03:00 committed by Greg Kroah-Hartman
parent 618d60dc74
commit 509d21f1c4

View file

@ -700,37 +700,21 @@ static struct miscdevice vtpmx_miscdev = {
.fops = &vtpmx_fops,
};
static int vtpmx_init(void)
{
return misc_register(&vtpmx_miscdev);
}
static void vtpmx_cleanup(void)
{
misc_deregister(&vtpmx_miscdev);
}
static int __init vtpm_module_init(void)
{
int rc;
rc = vtpmx_init();
if (rc) {
pr_err("couldn't create vtpmx device\n");
return rc;
}
workqueue = create_workqueue("tpm-vtpm");
if (!workqueue) {
pr_err("couldn't create workqueue\n");
rc = -ENOMEM;
goto err_vtpmx_cleanup;
return -ENOMEM;
}
return 0;
err_vtpmx_cleanup:
vtpmx_cleanup();
rc = misc_register(&vtpmx_miscdev);
if (rc) {
pr_err("couldn't create vtpmx device\n");
destroy_workqueue(workqueue);
}
return rc;
}
@ -738,7 +722,7 @@ static int __init vtpm_module_init(void)
static void __exit vtpm_module_exit(void)
{
destroy_workqueue(workqueue);
vtpmx_cleanup();
misc_deregister(&vtpmx_miscdev);
}
module_init(vtpm_module_init);