From: Edward Adam Davis eadavis@qq.com
[ Upstream commit 8cfc8cec1b4da88a47c243a11f384baefd092a50 ]
The device minor should not be cleared after the device is released.
Fixes: 9e14868dc952 ("media: mc: Clear minor number reservation at unregistration time") Cc: stable@vger.kernel.org Reported-by: syzbot+031d0cfd7c362817963f@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=031d0cfd7c362817963f Tested-by: syzbot+031d0cfd7c362817963f@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis eadavis@qq.com Signed-off-by: Sakari Ailus sakari.ailus@linux.intel.com Signed-off-by: Hans Verkuil hverkuil+cisco@kernel.org [ moved clear_bit from media_devnode_release callback to media_devnode_unregister before put_device ] Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/mc/mc-devnode.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c index 94abd042045da..6fd8885f5928e 100644 --- a/drivers/media/mc/mc-devnode.c +++ b/drivers/media/mc/mc-devnode.c @@ -50,11 +50,6 @@ static void media_devnode_release(struct device *cd) { struct media_devnode *devnode = to_media_devnode(cd);
- mutex_lock(&media_devnode_lock); - /* Mark device node number as free */ - clear_bit(devnode->minor, media_devnode_nums); - mutex_unlock(&media_devnode_lock); - /* Release media_devnode and perform other cleanups as needed. */ if (devnode->release) devnode->release(devnode); @@ -283,6 +278,7 @@ void media_devnode_unregister(struct media_devnode *devnode) /* Delete the cdev on this minor as well */ cdev_device_del(&devnode->cdev, &devnode->dev); devnode->media_dev = NULL; + clear_bit(devnode->minor, media_devnode_nums); mutex_unlock(&media_devnode_lock);
put_device(&devnode->dev);