Check the size of the response before accessing data in the
response packet. This is to avoid accessing data beyond the
end of the response.

Signed-off-by: Stefan Berger <[email protected]>
---
 drivers/char/tpm/tpm-interface.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 1c04a2d..6b6f099 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -687,7 +687,9 @@ int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 
*res_buf)
        cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
        rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
                              "attempting to read a pcr value");
-
+       if (rc == 0 &&
+           be32_to_cpu(cmd.header.out.length) < READ_PCR_RESULT_SIZE)
+               return -EFAULT;
        if (rc == 0)
                memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
                       TPM_DIGEST_SIZE);
-- 
2.4.3


------------------------------------------------------------------------------
Developer Access Program for Intel Xeon Phi Processors
Access to Intel Xeon Phi processor-based developer platforms.
With one year of Intel Parallel Studio XE.
Training and support from Colfax.
Order your platform today. http://sdm.link/xeonphi
_______________________________________________
tpmdd-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/tpmdd-devel

Reply via email to