[PATCH 4.8 09/57] b43legacy: fix debugfs crash

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>

commit 9c4a45b17e094a090e96beb1138e34c2a10c6b8c upstream.

This patch fixes a crash that happens because b43legacy's
debugfs code expects file->f_op to be a pointer to its own
b43legacy_debugfs_fops struct. This is no longer the case
since commit 9fd4dcece43a
("debugfs: prevent access to possibly dead file_operations at file open")

Reviewed-by: Nicolai Stange <nicstange@xxxxxxxxx>
Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/net/wireless/broadcom/b43legacy/debugfs.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/net/wireless/broadcom/b43legacy/debugfs.c
+++ b/drivers/net/wireless/broadcom/b43legacy/debugfs.c
@@ -221,7 +221,8 @@ static ssize_t b43legacy_debugfs_read(st
 		goto out_unlock;
 	}
 
-	dfops = container_of(file->f_op, struct b43legacy_debugfs_fops, fops);
+	dfops = container_of(debugfs_real_fops(file),
+			     struct b43legacy_debugfs_fops, fops);
 	if (!dfops->read) {
 		err = -ENOSYS;
 		goto out_unlock;
@@ -287,7 +288,8 @@ static ssize_t b43legacy_debugfs_write(s
 		goto out_unlock;
 	}
 
-	dfops = container_of(file->f_op, struct b43legacy_debugfs_fops, fops);
+	dfops = container_of(debugfs_real_fops(file),
+			     struct b43legacy_debugfs_fops, fops);
 	if (!dfops->write) {
 		err = -ENOSYS;
 		goto out_unlock;