On 10/23/17 4:32 AM, Borislav Petkov wrote: ... >> +static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp) >> +{ >> + int ret, err; >> + >> + ret = sev_platform_init(NULL, &argp->error); >> + if (ret) >> + return ret; >> + >> + ret = sev_do_cmd(cmd, 0, &argp->error); > So this ret value gets potentially overwritten here. You need > to either handle the case properly when sev_do_cmd() fails and > sev_platform_shutdown() gets to issue SEV_CMD_SHUTDOWN (i.e., when it > gets overwritten), or not write into ret at all by initializing it to 0 > at function entry. >
I am not sure if I am able to understand your feedback. The sev_platform_shutdown() is called unconditionally. 1) if sev_do_cmd() fails and sev_platform_shutdown() was success then 'ret' will contain theĀ error code from sev_do_cmd(). 2) if sev_do_cmd() was success but sev_platform_shutdown() fails then 'ret' will contain the error code from sev_platform_shutdown() 3) if both sev_do_cmd() and sev_platform_shutdown() fails then 'ret' will contain error code from the sev_platform_shutdown().