tpm: fix error return code in tpm2_get_cc_attrs_tbl()

If the total number of commands queried through TPM2_CAP_COMMANDS is
different from that queried through TPM2_CC_GET_CAPABILITY, it indicates
an unknown error. In this case, an appropriate error code -EFAULT should
be returned. However, we currently do not explicitly assign this error
code to 'rc'. As a result, 0 was incorrectly returned.

Cc: stable@vger.kernel.org
Fixes: 58472f5cd4f6("tpm: validate TPM 2.0 commands")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index eff1f12..c84d239 100644 (file)
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -656,6 +656,7 @@ int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
 
        if (nr_commands !=
            be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) {
+               rc = -EFAULT;
                tpm_buf_destroy(&buf);
                goto out;
        }