[PATCH 4.12 15/27] tpm: fix a kernel memory leak in tpm-sysfs.c

From: Greg Kroah-Hartman
Date: Mon Jul 10 2017 - 13:33:34 EST

4.12-stable review patch. If anyone has any objections, please let me know.


From: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>

commit 13b47cfcfc60495cde216eef4c01040d76174cbe upstream.

While cleaning up sysfs callback that prints EK we discovered a kernel
memory leak. This commit fixes the issue by zeroing the buffer used for
TPM command/response.

The leak happen when we use either tpm_vtpm_proxy, tpm_ibmvtpm or

Fixes: 0883743825e3 ("TPM: sysfs functions consolidation")
Reported-by: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
Tested-by: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: James Morris <james.l.morris@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/char/tpm/tpm-sysfs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/char/tpm/tpm-sysfs.c
+++ b/drivers/char/tpm/tpm-sysfs.c
@@ -36,9 +36,10 @@ static ssize_t pubek_show(struct device
ssize_t err;
int i, rc;
char *str = buf;
struct tpm_chip *chip = to_tpm_chip(dev);

+ memset(&tpm_cmd, 0, sizeof(tpm_cmd));
tpm_cmd.header.in = tpm_readpubek_header;
err = tpm_transmit_cmd(chip, NULL, &tpm_cmd, READ_PUBEK_RESULT_SIZE,