[PATCH 3/4] b43: fix debugfs crash

From: Christian Lamparter
Date: Sat Sep 17 2016 - 15:44:03 EST


This patch fixes a crash that happens because b43's
debugfs code expects file->f_op to be a pointer to
its own b43_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>
---
drivers/net/wireless/broadcom/b43/debugfs.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/broadcom/b43/debugfs.c b/drivers/net/wireless/broadcom/b43/debugfs.c
index b4bcd94..7704638 100644
--- a/drivers/net/wireless/broadcom/b43/debugfs.c
+++ b/drivers/net/wireless/broadcom/b43/debugfs.c
@@ -524,7 +524,8 @@ static ssize_t b43_debugfs_read(struct file *file, char __user *userbuf,
goto out_unlock;
}

- dfops = container_of(file->f_op, struct b43_debugfs_fops, fops);
+ dfops = container_of(debugfs_real_fops(file),
+ struct b43_debugfs_fops, fops);
if (!dfops->read) {
err = -ENOSYS;
goto out_unlock;
@@ -585,7 +586,8 @@ static ssize_t b43_debugfs_write(struct file *file,
goto out_unlock;
}

- dfops = container_of(file->f_op, struct b43_debugfs_fops, fops);
+ dfops = container_of(debugfs_real_fops(file),
+ struct b43_debugfs_fops, fops);
if (!dfops->write) {
err = -ENOSYS;
goto out_unlock;
--
2.9.3