This is a note to let you know that I've just added the patch titled tpm_tis: Check return values from get_burstcount. to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tpm_tis-check-return-values-from-get_burstcount.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 26a137e31ffe6fbfdb008554a8d9b3d55bd5c86e Mon Sep 17 00:00:00 2001 From: Josh Zimmerman <joshz@xxxxxxxxxx> Date: Thu, 27 Oct 2016 14:50:09 -0700 Subject: tpm_tis: Check return values from get_burstcount. From: Josh Zimmerman <joshz@xxxxxxxxxx> commit 26a137e31ffe6fbfdb008554a8d9b3d55bd5c86e upstream. If the TPM we're connecting to uses a static burst count, it will report a burst count of zero throughout the response read. However, get_burstcount assumes that a response of zero indicates that the TPM is not ready to receive more data. In this case, it returns a negative error code, which is passed on to tpm_tis_{write,read}_bytes as a u16, causing them to read/write far too many bytes. This patch checks for negative return codes and bails out from recv_data and tpm_tis_send_data. Fixes: 1107d065fdf1 (tpm_tis: Introduce intermediate layer for TPM access) Signed-off-by: Josh Zimmerman <joshz@xxxxxxxxxx> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/char/tpm/tpm_tis_core.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -185,7 +185,12 @@ static int recv_data(struct tpm_chip *ch TPM_STS_DATA_AVAIL | TPM_STS_VALID, chip->timeout_c, &priv->read_queue, true) == 0) { - burstcnt = min_t(int, get_burstcount(chip), count - size); + burstcnt = get_burstcount(chip); + if (burstcnt < 0) { + dev_err(&chip->dev, "Unable to read burstcount\n"); + return burstcnt; + } + burstcnt = min_t(int, burstcnt, count - size); rc = tpm_tis_read_bytes(priv, TPM_DATA_FIFO(priv->locality), burstcnt, buf + size); @@ -271,7 +276,13 @@ static int tpm_tis_send_data(struct tpm_ } while (count < len - 1) { - burstcnt = min_t(int, get_burstcount(chip), len - count - 1); + burstcnt = get_burstcount(chip); + if (burstcnt < 0) { + dev_err(&chip->dev, "Unable to read burstcount\n"); + rc = burstcnt; + goto out_err; + } + burstcnt = min_t(int, burstcnt, len - count - 1); rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality), burstcnt, buf + count); if (rc < 0) Patches currently in stable-queue which might be from joshz@xxxxxxxxxx are queue-4.9/tpm_tis-check-return-values-from-get_burstcount.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html