Merge tag 'driver-core-3.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fix from Greg Kroah-Hartman:
"Here's a single patch for the firmware core that resolves a reported
oops in the firmware core that people have been hitting."
* tag 'driver-core-3.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
firmware loader: fix use-after-free by double abort
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 4b1f926..01e2103 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -450,8 +450,18 @@
{
struct firmware_buf *buf = fw_priv->buf;
+ /*
+ * There is a small window in which user can write to 'loading'
+ * between loading done and disappearance of 'loading'
+ */
+ if (test_bit(FW_STATUS_DONE, &buf->status))
+ return;
+
set_bit(FW_STATUS_ABORT, &buf->status);
complete_all(&buf->completion);
+
+ /* avoid user action after loading abort */
+ fw_priv->buf = NULL;
}
#define is_fw_load_aborted(buf) \
@@ -528,7 +538,12 @@
struct device_attribute *attr, char *buf)
{
struct firmware_priv *fw_priv = to_firmware_priv(dev);
- int loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
+ int loading = 0;
+
+ mutex_lock(&fw_lock);
+ if (fw_priv->buf)
+ loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
+ mutex_unlock(&fw_lock);
return sprintf(buf, "%d\n", loading);
}
@@ -570,12 +585,12 @@
const char *buf, size_t count)
{
struct firmware_priv *fw_priv = to_firmware_priv(dev);
- struct firmware_buf *fw_buf = fw_priv->buf;
+ struct firmware_buf *fw_buf;
int loading = simple_strtol(buf, NULL, 10);
int i;
mutex_lock(&fw_lock);
-
+ fw_buf = fw_priv->buf;
if (!fw_buf)
goto out;
@@ -777,10 +792,6 @@
struct firmware_priv, timeout_work.work);
mutex_lock(&fw_lock);
- if (test_bit(FW_STATUS_DONE, &(fw_priv->buf->status))) {
- mutex_unlock(&fw_lock);
- return;
- }
fw_load_abort(fw_priv);
mutex_unlock(&fw_lock);
}
@@ -861,8 +872,6 @@
cancel_delayed_work_sync(&fw_priv->timeout_work);
- fw_priv->buf = NULL;
-
device_remove_file(f_dev, &dev_attr_loading);
err_del_bin_attr:
device_remove_bin_file(f_dev, &firmware_attr_data);