On 2018/05/06 7:07, Greg KH wrote: >> More likely wireless territory > > Ugh, that's what I get for writing emails before coffee in the > morning... > > Yes, you are right, this looks like a wireless issue. > > Now cc: linux-wireless. > Nope, if you look at previous fault injection messages... >From 7ddcaa3d4327d4f29d11053bd2011bf77ecf72af Mon Sep 17 00:00:00 2001 From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Date: Mon, 7 May 2018 14:19:50 +0900 Subject: [PATCH] driver core: Don't ignore class_dir_create_and_add() failure. syzbot is hitting WARN() at kernfs_add_one() [1]. This is because kernfs_create_link() is confused by previous device_add() call which continued without setting dev->kobj.parent field when get_device_parent() failed by memory allocation fault injection. Fix this by propagating the error from class_dir_create_and_add() to the calllers of get_device_parent(). [1] https://syzkaller.appspot.com/bug?id=fae0fb607989ea744526d1c082a5b8de6529116f Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Reported-by: syzbot <syzbot+df47f81c226b31d89fb1@xxxxxxxxxxxxxxxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/base/core.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index b610816..d680fd0 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1467,7 +1467,7 @@ class_dir_create_and_add(struct class *class, struct kobject *parent_kobj) dir = kzalloc(sizeof(*dir), GFP_KERNEL); if (!dir) - return NULL; + return ERR_PTR(-ENOMEM); dir->class = class; kobject_init(&dir->kobj, &class_dir_ktype); @@ -1477,7 +1477,7 @@ class_dir_create_and_add(struct class *class, struct kobject *parent_kobj) retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name); if (retval < 0) { kobject_put(&dir->kobj); - return NULL; + return ERR_PTR(retval); } return &dir->kobj; } @@ -1784,6 +1784,10 @@ int device_add(struct device *dev) parent = get_device(dev->parent); kobj = get_device_parent(dev, parent); + if (IS_ERR(kobj)) { + error = PTR_ERR(kobj); + goto parent_error; + } if (kobj) dev->kobj.parent = kobj; @@ -1882,6 +1886,7 @@ int device_add(struct device *dev) kobject_del(&dev->kobj); Error: cleanup_glue_dir(dev, glue_dir); +parent_error: put_device(parent); name_error: kfree(dev->p); @@ -2701,6 +2706,11 @@ int device_move(struct device *dev, struct device *new_parent, device_pm_lock(); new_parent = get_device(new_parent); new_parent_kobj = get_device_parent(dev, new_parent); + if (IS_ERR(new_parent_kobj)) { + error = PTR_ERR(new_parent_kobj); + put_device(new_parent); + goto out; + } pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev), __func__, new_parent ? dev_name(new_parent) : "<NULL>"); -- 1.8.3.1
