Patch "tpm, tpm_crb: fix unaligned read of the command buffer address" has been added to the 4.3-stable tree

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

tpm, tpm_crb: fix unaligned read of the command buffer address

to the 4.3-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-tpm_crb-fix-unaligned-read-of-the-command-buffer-address.patch
and it can be found in the queue-4.3 subdirectory.

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

From: Jarkko Sakkinen <[email protected]>
Date: Tue, 15 Sep 2015 20:05:40 +0300
Subject: tpm, tpm_crb: fix unaligned read of the command buffer address

From: Jarkko Sakkinen <[email protected]>

commit 149789ce9d472e6b4fd99336e779ab843754a96c upstream.

The command buffer address must be read with exactly two 32-bit reads. Otherwise, on some HW platforms, it seems that HW will abort the read operation, which causes CPU to fill the read bytes with 1's. Therefore, we cannot rely on memcpy_fromio() but must call ioread32() two times instead.

Also, this matches the PC Client Platform TPM Profile specification, which defines command buffer address with two 32-bit fields.

---
 drivers/char/tpm/tpm_crb.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

@@ -68,7 +68,8 @@ struct crb_control_area {
 	u32 int_enable;
 	u32 int_sts;
 	u32 cmd_size;
-	u64 cmd_pa;
+	u32 cmd_pa_low;
+	u32 cmd_pa_high;
 	u32 rsp_size;
 	u64 rsp_pa;
 } __packed;

@@ -263,8 +264,8 @@ static int crb_acpi_add(struct acpi_devi
 		return -ENOMEM;
 	}
 
-	memcpy_fromio(&pa, &priv->cca->cmd_pa, 8);
-	pa = le64_to_cpu(pa);
+	pa = ((u64) le32_to_cpu(ioread32(&priv->cca->cmd_pa_high)) << 32) |
+		(u64) le32_to_cpu(ioread32(&priv->cca->cmd_pa_low));
 	priv->cmd = devm_ioremap_nocache(dev, pa,
 					 ioread32(&priv->cca->cmd_size));
 	if (!priv->cmd) {

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

queue-4.3/tpm-revert-the-list-handling-logic-fixed-in-398a1e7.patch queue-4.3/tpm_tis-free-irq-after-probing.patch queue-4.3/tpm-tpm_crb-fix-unaligned-read-of-the-command-buffer-address.patch