[3.13.y.z extended stable] Patch "tpm: missing tpm_chip_put in tpm_get_random()" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    tpm: missing tpm_chip_put in tpm_get_random()

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.7.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From a118fe604ba41d43d679332e5a86b85730d0c83c Mon Sep 17 00:00:00 2001
From: Jarkko Sakkinen <jarkko.sakkinen at linux.intel.com>
Date: Fri, 9 May 2014 14:23:10 +0300
Subject: tpm: missing tpm_chip_put in tpm_get_random()

commit 3e14d83ef94a5806a865b85b513b4e891923c19b upstream.

Regression in 41ab999c. Call to tpm_chip_put is missing. This
will cause TPM device driver not to unload if tmp_get_random()
is called.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen at linux.intel.com>
Signed-off-by: Peter Huewe <peterhuewe at gmx.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/char/tpm/tpm-interface.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 6ae41d3..901b370 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -1400,13 +1400,13 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
 	int err, total = 0, retries = 5;
 	u8 *dest = out;

+	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
+		return -EINVAL;
+
 	chip = tpm_chip_find_get(chip_num);
 	if (chip == NULL)
 		return -ENODEV;

-	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
-		return -EINVAL;
-
 	do {
 		tpm_cmd.header.in = tpm_getrandom_header;
 		tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
@@ -1425,6 +1425,7 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
 		num_bytes -= recd;
 	} while (retries-- && total < max);

+	tpm_chip_put(chip);
 	return total ? total : -EIO;
 }
 EXPORT_SYMBOL_GPL(tpm_get_random);
--
1.9.1