From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Date: Mon, 12 Sep 2016 10:43:30 +0000 (+0300)
Subject: tpm: add check for minimum buffer size in tpm_transmit()
X-Git-Tag: v4.9-rc1~130^2~7
X-Git-Url: http://git.cascardo.eti.br/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=ebfd7532e985818a327906e011f3e43c8ddfdd74

tpm: add check for minimum buffer size in tpm_transmit()

tpm_transmit() does not check that bufsiz is at least TPM_HEADER_SIZE
before accessing data. This commit adds this check and returns -EINVAL
if it fails.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 3970f843acd1..8de61876f633 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -337,6 +337,9 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
 	u32 count, ordinal;
 	unsigned long stop;
 
+	if (bufsiz < TPM_HEADER_SIZE)
+		return -EINVAL;
+
 	if (bufsiz > TPM_BUFSIZE)
 		bufsiz = TPM_BUFSIZE;