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| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2018-05-07 12:10:31 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-14 16:37:46 +0200 |
| commit | 84d0c27d6233a9ba0578b20f5a09701eb66cee42 (patch) | |
| tree | d7da3b81c9654509f1db78e986e4975e2a69b8e2 | |
| parent | Merge 4.17-rc3 into driver-core-next (diff) | |
| download | linux-84d0c27d6233a9ba0578b20f5a09701eb66cee42.tar.xz linux-84d0c27d6233a9ba0578b20f5a09701eb66cee42.zip | |
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@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+df47f81c226b31d89fb1@syzkaller.appspotmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/base/core.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index b610816eb887..d680fd030316 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 @@ done: 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>"); |