tpm: missing tpm_chip_put in tpm_get_random()

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.

Cc: <stable@vger.kernel.org> # 3.7+
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index d175fb8e719a..bef6cceffc3a 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -991,13 +991,13 @@ 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);
@@ -1016,6 +1016,7 @@ 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);