On 5/15/23 18:25, Jarkko Sakkinen wrote:
From: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxx> /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@xxxxxxxxxxxxxxx Fixes: 6f99612e2500 ("tpm: Proxy driver for supporting multiple emulated TPMs") Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxx> --- v2: - Replace vtpmx_cleanup() with destroy_workqueue(): https://lore.kernel.org/linux-integrity/CSLCEYDKKWWE.36POIXVT65SLE@suppilovahvero/ - Fix typo: https://lore.kernel.org/linux-integrity/4651cf1c-423d-05c2-b4c3-9d829a2eadf4@xxxxxxxxxxxxx/ --- drivers/char/tpm/tpm_vtpm_proxy.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-) 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 @@ 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);
Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
