From: Christian Lamparter <chunkeey@googlemail.com>
Date: Sat, 17 Sep 2016 19:43:04 +0000 (+0200)
Subject: b43legacy: fix debugfs crash
X-Git-Tag: v4.9-rc1~148^2~7
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9c4a45b17e094a090e96beb1138e34c2a10c6b8c;p=karo-tx-linux.git

b43legacy: fix debugfs crash

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@gmail.com>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Cc: stable <stable@vger.kernel.org> # 4.7+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/net/wireless/broadcom/b43legacy/debugfs.c b/drivers/net/wireless/broadcom/b43legacy/debugfs.c
index 090910ea259e..82ef56ed7ca1 100644
--- 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(struct file *file, char __user *userbuf,
 		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(struct file *file,
 		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;