On Fri, Dec 17, 2021 at 04:34:28PM +0800, Wei Yongjun wrote:
> 'ftdi' is alloced when probe device, but not free on device disconnect,
> this cause a memory leak as follows:
>
> unreferenced object 0xffff88800d584000 (size 8400):
> comm "kworker/0:2", pid 3809, jiffies 4295453055 (age 13.784s)
> hex dump (first 32 bytes):
> 00 40 58 0d 80 88 ff ff 00 40 58 0d 80 88 ff ff .@X......@X.....
> 00 00 00 00 00 00 00 00 00 00 00 00 ad 4e ad de .............N..
> backtrace:
> [<000000000d47f947>] kmalloc_order_trace+0x19/0x110 mm/slab_common.c:960
> [<000000008548ac68>] ftdi_elan_probe+0x8c/0x880 drivers/usb/misc/ftdi-elan.c:2647
> [<000000007f73e422>] usb_probe_interface+0x31b/0x800 drivers/usb/core/driver.c:396
> [<00000000fe8d07fc>] really_probe+0x299/0xc30 drivers/base/dd.c:517
> [<0000000005da7d32>] __driver_probe_device+0x357/0x500 drivers/base/dd.c:751
> [<000000003c2c9579>] driver_probe_device+0x4e/0x140 drivers/base/dd.c:781
>
> Fix it by freeing 'ftdi' after nobody use it.
>
> Fixes: a5c66e4b2418 ("USB: ftdi-elan: client driver for ELAN Uxxx adapters")
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
>
> diff --git a/drivers/usb/misc/ftdi-elan.c b/drivers/usb/misc/ftdi-elan.c
> index e5a8fcdbb78e..6c38c62d29b2 100644
> --- a/drivers/usb/misc/ftdi-elan.c
> +++ b/drivers/usb/misc/ftdi-elan.c
> @@ -202,6 +202,7 @@ static void ftdi_elan_delete(struct kref *kref)
> mutex_unlock(&ftdi_module_lock);
> kfree(ftdi->bulk_in_buffer);
> ftdi->bulk_in_buffer = NULL;
> + kfree(ftdi);
> }
Wow, yes, good catch. Funny no one has ever noticed that before :(
greg k-h
