On Fri, 2021-01-29 at 01:56 +0200, jarkko@xxxxxxxxxx wrote: > From: Jarkko Sakkinen <jarkko@xxxxxxxxxx> > > When tpm_get_random() was introduced, it defined the following API for the > return value: > > 1. A positive value tells how many bytes of random data was generated. > 2. A negative value on error. > > However, in the call sites the API was used incorrectly, i.e. as it would > only return negative values and otherwise zero. Returning he positive read > counts to the user space does not make any possible sense. > > Fix this by returning -EIO when tpm_get_random() returns a positive value. > > Fixes: 41ab999c80f1 ("tpm: Move tpm_get_random api into the TPM device driver") > Cc: stable@xxxxxxxxxxxxxxx > Cc: Mimi Zohar <zohar@xxxxxxxxxxxxx> > Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> > Cc: David Howells <dhowells@xxxxxxxxxx> > Cc: Kent Yoder <key@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> thanks, Reviewed-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>