Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull TPM bugfixes from James Morris.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  tpm: Propagate error from tpm_transmit to fix a timeout hang
  driver/char/tpm: fix regression causesd by ppi

3 files changed, 33 insertions, 18 deletions

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index f26afdb1a702..93211df52aab 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -1182,17 +1182,20 @@ ssize_t tpm_write(struct file *file, const char __user *buf,
 		  size_t size, loff_t *off)
 {
 	struct tpm_chip *chip = file->private_data;
-	size_t in_size = size, out_size;
+	size_t in_size = size;
+	ssize_t out_size;
 
 	/* cannot perform a write until the read has cleared
-	   either via tpm_read or a user_read_timer timeout */
-	while (atomic_read(&chip->data_pending) != 0)
-		msleep(TPM_TIMEOUT);
-
-	mutex_lock(&chip->buffer_mutex);
+	   either via tpm_read or a user_read_timer timeout.
+	   This also prevents splitted buffered writes from blocking here.
+	*/
+	if (atomic_read(&chip->data_pending) != 0)
+		return -EBUSY;
 
 	if (in_size > TPM_BUFSIZE)
-		in_size = TPM_BUFSIZE;
+		return -E2BIG;
+
+	mutex_lock(&chip->buffer_mutex);
 
 	if (copy_from_user
 	    (chip->data_buffer, (void __user *) buf, in_size)) {
@@ -1202,6 +1205,10 @@ ssize_t tpm_write(struct file *file, const char __user *buf,
 
 	/* atomic tpm command send and result receive */
 	out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
+	if (out_size < 0) {
+		mutex_unlock(&chip->buffer_mutex);
+		return out_size;
+	}
 
 	atomic_set(&chip->data_pending, out_size);
 	mutex_unlock(&chip->buffer_mutex);
@@ -1259,6 +1266,7 @@ void tpm_remove_hardware(struct device *dev)
 
 	misc_deregister(&chip->vendor.miscdev);
 	sysfs_remove_group(&dev->kobj, chip->vendor.attr_group);
+	tpm_remove_ppi(&dev->kobj);
 	tpm_bios_log_teardown(chip->bios_dir);
 
 	/* write it this way to be explicit (chip->dev == dev) */
@@ -1476,7 +1484,7 @@ struct tpm_chip *tpm_register_hardware(struct device *dev,
 		goto put_device;
 	}
 
-	if (sys_add_ppi(&dev->kobj)) {
+	if (tpm_add_ppi(&dev->kobj)) {
 		misc_deregister(&chip->vendor.miscdev);
 		goto put_device;
 	}
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 02c266aa2bf7..8ef7649a50aa 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -329,10 +329,15 @@ extern int wait_for_tpm_stat(struct tpm_chip *, u8, unsigned long,
 			     wait_queue_head_t *);
 
 #ifdef CONFIG_ACPI
-extern ssize_t sys_add_ppi(struct kobject *parent);
+extern int tpm_add_ppi(struct kobject *);
+extern void tpm_remove_ppi(struct kobject *);
 #else
-static inline ssize_t sys_add_ppi(struct kobject *parent)
+static inline int tpm_add_ppi(struct kobject *parent)
 {
 	return 0;
 }
+
+static inline void tpm_remove_ppi(struct kobject *parent)
+{
+}
 #endif
diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
index f27b58cfae98..720ebcf29fdf 100644
--- a/drivers/char/tpm/tpm_ppi.c
+++ b/drivers/char/tpm/tpm_ppi.c
@@ -444,18 +444,20 @@ static struct attribute *ppi_attrs[] = {
 	&dev_attr_vs_operations.attr, NULL,
 };
 static struct attribute_group ppi_attr_grp = {
+	.name = "ppi",
 	.attrs = ppi_attrs
 };
 
-ssize_t sys_add_ppi(struct kobject *parent)
+int tpm_add_ppi(struct kobject *parent)
 {
-	struct kobject *ppi;
-	ppi = kobject_create_and_add("ppi", parent);
-	if (sysfs_create_group(ppi, &ppi_attr_grp))
-		return -EFAULT;
-	else
-		return 0;
+	return sysfs_create_group(parent, &ppi_attr_grp);
+}
+EXPORT_SYMBOL_GPL(tpm_add_ppi);
+
+void tpm_remove_ppi(struct kobject *parent)
+{
+	sysfs_remove_group(parent, &ppi_attr_grp);
 }
-EXPORT_SYMBOL_GPL(sys_add_ppi);
+EXPORT_SYMBOL_GPL(tpm_remove_ppi);
 
 MODULE_LICENSE("GPL");