From f4032d615f90970d6c3ac1d9c0bce3351eb4445c Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen Date: Tue, 16 May 2023 01:25:54 +0300 Subject: tpm: tpm_vtpm_proxy: fix a race condition in /dev/vtpmx creation /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: 6f99612e2500 ("tpm: Proxy driver for supporting multiple emulated TPMs") Reviewed-by: Stefan Berger Signed-off-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_vtpm_proxy.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c index 5c865987ba5c..30e953988cab 100644 --- a/drivers/char/tpm/tpm_vtpm_proxy.c +++ b/drivers/char/tpm/tpm_vtpm_proxy.c @@ -683,37 +683,21 @@ 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; } @@ -721,7 +705,7 @@ err_vtpmx_cleanup: static void __exit vtpm_module_exit(void) { destroy_workqueue(workqueue); - vtpmx_cleanup(); + misc_deregister(&vtpmx_miscdev); } module_init(vtpm_module_init); -- cgit v1.2.3