This is a note to let you know that I've just added the patch titled
tpm: tpm_vtpm_proxy: fix a race condition in /dev/vtpmx creation
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tpm-tpm_vtpm_proxy-fix-a-race-condition-in-dev-vtpmx-creation.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f4032d615f90970d6c3ac1d9c0bce3351eb4445c Mon Sep 17 00:00:00 2001
From: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxx>
Date: Tue, 16 May 2023 01:25:54 +0300
Subject: tpm: tpm_vtpm_proxy: fix a race condition in /dev/vtpmx creation
From: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxx>
commit f4032d615f90970d6c3ac1d9c0bce3351eb4445c 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@xxxxxxxxxxxxxxx
Fixes: 6f99612e2500 ("tpm: Proxy driver for supporting multiple emulated TPMs")
Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm_vtpm_proxy.c | 30 +++++++-----------------------
1 file changed, 7 insertions(+), 23 deletions(-)
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -693,37 +693,21 @@ 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;
}
@@ -731,7 +715,7 @@ err_vtpmx_cleanup:
static void __exit vtpm_module_exit(void)
{
destroy_workqueue(workqueue);
- vtpmx_cleanup();
+ misc_deregister(&vtpmx_miscdev);
}
module_init(vtpm_module_init);
Patches currently in stable-queue which might be from jarkko.sakkinen@xxxxxxx are
queue-5.4/tpm-tpm_vtpm_proxy-fix-a-race-condition-in-dev-vtpmx-creation.patch
