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authorLinus Torvalds <torvalds@linux-foundation.org>2013-06-22 09:02:44 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2013-06-22 09:02:44 -1000
commite10e57718544a321b97c036cf124d2a0b3f91d38 (patch)
tree88dadc46ca90eff37a966fb9437f1fb216d2f4f3
parentb71055beaaa7fddbbfd2a60644dcb308408f686c (diff)
parent875979368eb4cfecff9f0e97625b90cc6009269d (diff)
downloadlinux-linaro-stable-e10e57718544a321b97c036cf124d2a0b3f91d38.tar.gz
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
-rw-r--r--drivers/base/firmware_class.c27
1 files changed, 18 insertions, 9 deletions
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 4b1f9265887f..01e21037d8fe 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -450,8 +450,18 @@ static void fw_load_abort(struct firmware_priv *fw_priv)
{
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 @@ static ssize_t firmware_loading_show(struct device *dev,
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 @@ static ssize_t firmware_loading_store(struct device *dev,
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 @@ static void firmware_class_timeout_work(struct work_struct *work)
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 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
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);