On 7/8/21 5:52 AM, 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). Fixes: 6f99612e2500 ("tpm: Proxy driver for supporting multiple emulated TPMs") Signed-off-by: Saubhik Mukherjee <saubhik.mukherjee@xxxxxxxxx>
Tested-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>