Re: [PATCH] udlfb: Fix memory leak in dlfb_usb_probe

[Daniel Vetter]

On Tue, Dec 15, 2020 at 02:30:22PM +0800, qiang.zhang@xxxxxxxxxxxxx wrote:
> From: Zqiang <qiang.zhang@xxxxxxxxxxxxx>
> 
> The dlfb_alloc_urb_list function is called in dlfb_usb_probe function,
> after that if an error occurs, the dlfb_free_urb_list function need to
> be called.
> 
> BUG: memory leak
> unreferenced object 0xffff88810adde100 (size 32):
>   comm "kworker/1:0", pid 17, jiffies 4294947788 (age 19.520s)
>   hex dump (first 32 bytes):
>     10 30 c3 0d 81 88 ff ff c0 fa 63 12 81 88 ff ff  .0........c.....
>     00 30 c3 0d 81 88 ff ff 80 d1 3a 08 81 88 ff ff  .0........:.....
>   backtrace:
>     [<0000000019512953>] kmalloc include/linux/slab.h:552 [inline]
>     [<0000000019512953>] kzalloc include/linux/slab.h:664 [inline]
>     [<0000000019512953>] dlfb_alloc_urb_list drivers/video/fbdev/udlfb.c:1892 [inline]
>     [<0000000019512953>] dlfb_usb_probe.cold+0x289/0x988 drivers/video/fbdev/udlfb.c:1704
>     [<0000000072160152>] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396
>     [<00000000a8d6726f>] really_probe+0x159/0x480 drivers/base/dd.c:554
>     [<00000000c3ce4b0e>] driver_probe_device+0x84/0x100 drivers/base/dd.c:738
>     [<00000000e942e01c>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:844
>     [<00000000de0a5a5c>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:431
>     [<00000000463fbcb4>] __device_attach+0x122/0x250 drivers/base/dd.c:912
>     [<00000000b881a711>] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:491
>     [<00000000364bbda5>] device_add+0x5ac/0xc30 drivers/base/core.c:2936
>     [<00000000eecca418>] usb_set_configuration+0x9de/0xb90 drivers/usb/core/message.c:2159
>     [<00000000edfeca2d>] usb_generic_driver_probe+0x8c/0xc0 drivers/usb/core/generic.c:238
>     [<000000001830872b>] usb_probe_device+0x5c/0x140 drivers/usb/core/driver.c:293
>     [<00000000a8d6726f>] really_probe+0x159/0x480 drivers/base/dd.c:554
>     [<00000000c3ce4b0e>] driver_probe_device+0x84/0x100 drivers/base/dd.c:738
>     [<00000000e942e01c>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:844
>     [<00000000de0a5a5c>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:431
> 
> Reported-by: syzbot+c9e365d7f450e8aa615d@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Zqiang <qiang.zhang@xxxxxxxxxxxxx>

Queued up in drm-misc-next, thanks for your patch.
-Daniel

> ---
>  drivers/video/fbdev/udlfb.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c
> index f9b3c1cb9530..b9cdd02c1000 100644
> --- a/drivers/video/fbdev/udlfb.c
> +++ b/drivers/video/fbdev/udlfb.c
> @@ -1017,6 +1017,7 @@ static void dlfb_ops_destroy(struct fb_info *info)
>  	}
>  	vfree(dlfb->backing_buffer);
>  	kfree(dlfb->edid);
> +	dlfb_free_urb_list(dlfb);
>  	usb_put_dev(dlfb->udev);
>  	kfree(dlfb);
>  
> -- 
> 2.17.1
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch