This is a note to let you know that I've just added the patch titled

tpm_i2c_nuvoton: fix potential buffer overruns caused by bit glitches on the bus

to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: tpm_i2c_nuvoton-fix-potential-buffer-overruns-caused-by-bit-glitches-on-the-bus.patch and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From f9d4d9b5a5ef2f017bc344fb65a58a902517173b Mon Sep 17 00:00:00 2001

From: Jeremy Boone jeremy.boone@nccgroup.trust Date: Thu, 8 Feb 2018 12:31:16 -0800 Subject: tpm_i2c_nuvoton: fix potential buffer overruns caused by bit glitches on the bus

From: Jeremy Boone jeremy.boone@nccgroup.trust

commit f9d4d9b5a5ef2f017bc344fb65a58a902517173b upstream.

Discrete TPMs are often connected over slow serial buses which, on some platforms, can have glitches causing bit flips. In all the driver _recv() functions, we need to use a u32 to unmarshal the response size, otherwise a bit flip of the 31st bit would cause the expected variable to go negative, which would then try to read a huge amount of data. Also sanity check that the expected amount of data is large enough for the TPM header.

Signed-off-by: Jeremy Boone jeremy.boone@nccgroup.trust Cc: stable@vger.kernel.org Signed-off-by: James Bottomley James.Bottomley@HansenPartnership.com Reviewed-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: James Morris james.morris@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/char/tpm/tpm_i2c_nuvoton.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/char/tpm/tpm_i2c_nuvoton.c +++ b/drivers/char/tpm/tpm_i2c_nuvoton.c @@ -281,7 +281,11 @@ static int i2c_nuvoton_recv(struct tpm_c struct device *dev = chip->dev.parent; struct i2c_client *client = to_i2c_client(dev); s32 rc; - int expected, status, burst_count, retries, size = 0; + int status; + int burst_count; + int retries; + int size = 0; + u32 expected;

if (count < TPM_HEADER_SIZE) { i2c_nuvoton_ready(chip); /* return to idle */ @@ -323,7 +327,7 @@ static int i2c_nuvoton_recv(struct tpm_c * to machine native */ expected = be32_to_cpu(*(__be32 *) (buf + 2)); - if (expected > count) { + if (expected > count || expected < size) { dev_err(dev, "%s() expected > count\n", __func__); size = -EIO; continue;

Patches currently in stable-queue which might be from jeremy.boone@nccgroup.trust are

queue-4.15/tpm-fix-potential-buffer-overruns-caused-by-bit-glitches-on-the-bus.patch queue-4.15/tpm_i2c_nuvoton-fix-potential-buffer-overruns-caused-by-bit-glitches-on-the-bus.patch queue-4.15/tpm-st33zp24-fix-potential-buffer-overruns-caused-by-bit-glitches-on-the-bus.patch queue-4.15/tpm_i2c_infineon-fix-potential-buffer-overruns-caused-by-bit-glitches-on-the-bus.patch queue-4.15/tpm_tis-fix-potential-buffer-overruns-caused-by-bit-glitches-on-the-bus.patch