This is a note to let you know that I've just added the patch titled
tpm: fix potential buffer overruns caused by bit glitches on the bus
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tpm-fix-potential-buffer-overruns-caused-by-bit-glitches-on-the-bus.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3be23274755ee85771270a23af7691dc9b3a95db Mon Sep 17 00:00:00 2001
From: Jeremy Boone <jeremy.boone@nccgroup.trust>
Date: Thu, 8 Feb 2018 12:28:08 -0800
Subject: tpm: fix potential buffer overruns caused by bit glitches on the bus
From: Jeremy Boone <jeremy.boone@nccgroup.trust>
commit 3be23274755ee85771270a23af7691dc9b3a95db upstream.
Discrete TPMs are often connected over slow serial buses which, on
some platforms, can have glitches causing bit flips. If a bit does
flip it could cause an overrun if it's in one of the size parameters,
so sanity check that we're not overrunning the provided buffer when
doing a memcpy().
Signed-off-by: Jeremy Boone <jeremy.boone@nccgroup.trust>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Signed-off-by: James Morris <james.morris@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm-interface.c | 5 +++++
drivers/char/tpm/tpm2-cmd.c | 6 ++++++
2 files changed, 11 insertions(+)
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -1040,6 +1040,11 @@ int tpm_get_random(u32 chip_num, u8 *out
break;
recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
+ if (recd > num_bytes) {
+ total = -EFAULT;
+ break;
+ }
+
memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
dest += recd;
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -622,6 +622,11 @@ static int tpm2_unseal_cmd(struct tpm_ch
if (!rc) {
data_len = be16_to_cpup(
(__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
+ if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE + 1) {
+ rc = -EFAULT;
+ goto out;
+ }
+
data = &buf.data[TPM_HEADER_SIZE + 6];
memcpy(payload->key, data, data_len - 1);
@@ -629,6 +634,7 @@ static int tpm2_unseal_cmd(struct tpm_ch
payload->migratable = data[data_len - 1];
}
+out:
tpm_buf_destroy(&buf);
return rc;
}
Patches currently in stable-queue which might be from jeremy.boone@nccgroup.trust are
queue-4.4/tpm-fix-potential-buffer-overruns-caused-by-bit-glitches-on-the-bus.patch
queue-4.4/tpm_tis-fix-potential-buffer-overruns-caused-by-bit-glitches-on-the-bus.patch