Patch "tpm: fix potential buffer overruns caused by bit glitches on the bus" has been added to the 4.15-stable tree

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 4.15-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-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Jeremy Boone <[email protected]>
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 <[email protected]>

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().

---
 drivers/char/tpm/tpm-interface.c |    4 ++++
 drivers/char/tpm/tpm2-cmd.c      |    4 ++++
 2 files changed, 8 insertions(+)

@@ -1228,6 +1228,10 @@ 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;
+		}
 
 		rlength = be32_to_cpu(tpm_cmd.header.out.length);
 		if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +

@@ -683,6 +683,10 @@ 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;
+		}
 
 		rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)
 					->header.out.length);

Patches currently in stable-queue which might be from [email protected] 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