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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-06-19 20:26:43 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-06-19 20:26:43 -0700
commit7068cb07563d8f001e83a2836ccf1cef6518aea4 (patch)
tree1b708c157ec11f8be7f72b1db3ae3b2f903a760d /drivers/base/firmware_class.c
parentMerge 3.10-rc6 into driver-core-next (diff)
parentfirmware loader: fix use-after-free by double abort (diff)
downloadlinux-dev-7068cb07563d8f001e83a2836ccf1cef6518aea4.tar.xz
linux-dev-7068cb07563d8f001e83a2836ccf1cef6518aea4.zip
Merge branch 'driver-core-linus' into driver-core-next
This resolves the merge issues with drivers/base/firmware_class.c Thanks to Ming Lei for the patch and hints on how to resolve it. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/firmware_class.c')
-rw-r--r--drivers/base/firmware_class.c48
1 files changed, 32 insertions, 16 deletions
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 6ede2292f67e..7fefcb5acfbf 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -452,13 +452,30 @@ static struct firmware_priv *to_firmware_priv(struct device *dev)
return container_of(dev, struct firmware_priv, dev);
}
-static void fw_load_abort(struct firmware_buf *buf)
+static void __fw_load_abort(struct firmware_buf *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;
+
list_del_init(&buf->pending_list);
set_bit(FW_STATUS_ABORT, &buf->status);
complete_all(&buf->completion);
}
+static void fw_load_abort(struct firmware_priv *fw_priv)
+{
+ struct firmware_buf *buf = fw_priv->buf;
+
+ __fw_load_abort(buf);
+
+ /* avoid user action after loading abort */
+ fw_priv->buf = NULL;
+}
+
#define is_fw_load_aborted(buf) \
test_bit(FW_STATUS_ABORT, &(buf)->status)
@@ -470,7 +487,7 @@ static int fw_shutdown_notify(struct notifier_block *unused1,
{
mutex_lock(&fw_lock);
while (!list_empty(&pending_fw_head))
- fw_load_abort(list_first_entry(&pending_fw_head,
+ __fw_load_abort(list_first_entry(&pending_fw_head,
struct firmware_buf,
pending_list));
mutex_unlock(&fw_lock);
@@ -550,7 +567,12 @@ 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);
}
@@ -592,12 +614,12 @@ 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;
@@ -635,7 +657,7 @@ static ssize_t firmware_loading_store(struct device *dev,
dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
/* fallthrough */
case -1:
- fw_load_abort(fw_buf);
+ fw_load_abort(fw_priv);
break;
}
out:
@@ -703,7 +725,7 @@ static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
new_pages = kmalloc(new_array_size * sizeof(void *),
GFP_KERNEL);
if (!new_pages) {
- fw_load_abort(buf);
+ fw_load_abort(fw_priv);
return -ENOMEM;
}
memcpy(new_pages, buf->pages,
@@ -720,7 +742,7 @@ static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
if (!buf->pages[buf->nr_pages]) {
- fw_load_abort(buf);
+ fw_load_abort(fw_priv);
return -ENOMEM;
}
buf->nr_pages++;
@@ -800,11 +822,7 @@ 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->buf);
+ fw_load_abort(fw_priv);
mutex_unlock(&fw_lock);
}
@@ -886,8 +904,6 @@ 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);
@@ -922,7 +938,7 @@ static void kill_requests_without_uevent(void)
mutex_lock(&fw_lock);
list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
if (!buf->need_uevent)
- fw_load_abort(buf);
+ __fw_load_abort(buf);
}
mutex_unlock(&fw_lock);
}