| Message ID | 20230515222554.2783592-1-jarkko@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] tpm: tpm_vtpm_proxy: fix a race condition in /dev/vtpmx creation | expand |
On 5/15/23 18:25, Jarkko Sakkinen wrote: > From: Jarkko Sakkinen <jarkko.sakkinen@tuni.fi> > > /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") > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@tuni.fi> > --- > 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@linux.ibm.com/ > --- > 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@linux.ibm.com>
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);