[tpmdd-devel] [PATCH V2 04/12] tpm: Use interface timeouts returned from the TPM

[Stefan B. <st...@li...>]

The TPM driver currently discards the interface timeout values returned
from the TPM. The check of the response packet needs to consider that
the return_code field is 0 on success and the size of the expected
packet is equivalent to the header size + u32 length indicator for the
TPM_GetCapability() result + 4 interface timeout indicators of type u32.

Signed-off-by: Stefan Berger <st...@li...>

Index: linux-2.6/drivers/char/tpm/tpm.c
===================================================================
--- linux-2.6.orig/drivers/char/tpm/tpm.c
+++ linux-2.6/drivers/char/tpm/tpm.c
@@ -545,9 +545,10 @@ void tpm_get_timeouts(struct tpm_chip *c
 	if (rc)
 		goto duration;
 
-	if (be32_to_cpu(tpm_cmd.header.out.length)
-	    != 4 * sizeof(u32))
-		goto duration;
+	if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
+	    be32_to_cpu(tpm_cmd.header.out.length)
+	    != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
+		return;
 
 	timeout_cap = &tpm_cmd.params.getcap_out.cap.timeout;
 	/* Don't overwrite default if value is 0 */