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authorJarkko Sakkinen <jarkko.sakkinen@tuni.fi>2023-05-16 01:25:54 +0300
committerJarkko Sakkinen <jarkko@kernel.org>2023-07-17 22:32:30 +0300
commitf4032d615f90970d6c3ac1d9c0bce3351eb4445c (patch)
treeda3eb8d9bc684580b0d381c30df18f6e22765779 /drivers/char
parentfdf0eaf11452d72945af31804e2a1048ee1b574c (diff)
downloadlinux-f4032d615f90970d6c3ac1d9c0bce3351eb4445c.tar.xz
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 <stefanb@linux.ibm.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@tuni.fi> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/tpm_vtpm_proxy.c30
1 files 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 @@ err_vtpmx_cleanup:
static void __exit vtpm_module_exit(void)
{
destroy_workqueue(workqueue);
- vtpmx_cleanup();
+ misc_deregister(&vtpmx_miscdev);
}
module_init(vtpm_module_init);