On 6/30/21 2:35 AM, Jarkko Sakkinen wrote:
On Tue, Jun 29, 2021 at 08:27:00PM +0300, Jarkko Sakkinen wrote:
On Wed, Jun 23, 2021 at 06:52:26PM +0530, Saubhik Mukherjee wrote:
vtpm_module_init calls vtpmx_init which calls misc_register. The file
operations callbacks are registered. So, vtpmx_fops_ioctl can execute in
parallel with rest of vtpm_module_init. vtpmx_fops_ioctl calls
vtpmx_ioc_new_dev, which calls vtpm_proxy_create_device, which calls
vtpm_proxy_work_start, which could read uninitialized workqueue.
To avoid this, create workqueue before vtpmx init.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Saubhik Mukherjee <saubhik.mukherjee@xxxxxxxxx>
---
drivers/char/tpm/tpm_vtpm_proxy.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)
diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c
index 91c772e38bb5..225dfa026a8f 100644
--- a/drivers/char/tpm/tpm_vtpm_proxy.c
+++ b/drivers/char/tpm/tpm_vtpm_proxy.c
@@ -697,23 +697,22 @@ 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;
+ }
+
+ rc = vtpmx_init();
+ if (rc) {
+ pr_err("couldn't create vtpmx device\n");
+ goto err_destroy_workqueue;
}
return 0;
-err_vtpmx_cleanup:
- vtpmx_cleanup();
+err_destroy_workqueue:
+ destroy_workqueue(workqueue);
return rc;
}
--
2.30.2
Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
Taking reviewed-by back.
You're lacking fixes tag. Please re-send with one.
/Jarkko
Thank you for noticing. I sent the patch containing the Fixes tag in
reply to your last message. (https://lkml.org/lkml/2021/6/30/104)
