[PATCH v2] misc/uss720: fix memory leak in uss720_probe

[PATCH v2] misc/uss720: fix memory leak in uss720_probe

[Dongliang Mu]

uss720_probe forgets to decrease the refcount of usbdev in uss720_probe.
Fix this by decreasing the refcount of usbdev by usb_put_dev.

BUG: memory leak
unreferenced object 0xffff888101113800 (size 2048):
  comm "kworker/0:1", pid 7, jiffies 4294956777 (age 28.870s)
  hex dump (first 32 bytes):
    ff ff ff ff 31 00 00 00 00 00 00 00 00 00 00 00  ....1...........
    00 00 00 00 00 00 00 00 00 00 00 00 03 00 00 00  ................
  backtrace:
    [<ffffffff82b8e822>] kmalloc include/linux/slab.h:554 [inline]
    [<ffffffff82b8e822>] kzalloc include/linux/slab.h:684 [inline]
    [<ffffffff82b8e822>] usb_alloc_dev+0x32/0x450 drivers/usb/core/usb.c:582
    [<ffffffff82b98441>] hub_port_connect drivers/usb/core/hub.c:5129 [inline]
    [<ffffffff82b98441>] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline]
    [<ffffffff82b98441>] port_event drivers/usb/core/hub.c:5509 [inline]
    [<ffffffff82b98441>] hub_event+0x1171/0x20c0 drivers/usb/core/hub.c:5591
    [<ffffffff81259229>] process_one_work+0x2c9/0x600 kernel/workqueue.c:2275
    [<ffffffff81259b19>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2421
    [<ffffffff81261228>] kthread+0x178/0x1b0 kernel/kthread.c:292
    [<ffffffff8100227f>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Reported-by: syzbot+636c58f40a86b4a879e7@syzkaller.appspotmail.com
Fixes: 0f36163d3abe ("usb: fix uss720 schedule with interrupts off")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
---
 drivers/usb/misc/uss720.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/misc/uss720.c b/drivers/usb/misc/uss720.c
index b5d661644263..748139d26263 100644
--- a/drivers/usb/misc/uss720.c
+++ b/drivers/usb/misc/uss720.c
@@ -736,6 +736,7 @@ static int uss720_probe(struct usb_interface *intf,
 	parport_announce_port(pp);
 
 	usb_set_intfdata(intf, pp);
+	usb_put_dev(usbdev);
 	return 0;
 
 probe_abort:
-- 
2.25.1

Re: [PATCH v2] misc/uss720: fix memory leak in uss720_probe

[Greg KH]

On Fri, May 14, 2021 at 08:34:25PM +0800, Dongliang Mu wrote:
> uss720_probe forgets to decrease the refcount of usbdev in uss720_probe.
> Fix this by decreasing the refcount of usbdev by usb_put_dev.
> 
> BUG: memory leak
> unreferenced object 0xffff888101113800 (size 2048):
>   comm "kworker/0:1", pid 7, jiffies 4294956777 (age 28.870s)
>   hex dump (first 32 bytes):
>     ff ff ff ff 31 00 00 00 00 00 00 00 00 00 00 00  ....1...........
>     00 00 00 00 00 00 00 00 00 00 00 00 03 00 00 00  ................
>   backtrace:
>     [<ffffffff82b8e822>] kmalloc include/linux/slab.h:554 [inline]
>     [<ffffffff82b8e822>] kzalloc include/linux/slab.h:684 [inline]
>     [<ffffffff82b8e822>] usb_alloc_dev+0x32/0x450 drivers/usb/core/usb.c:582
>     [<ffffffff82b98441>] hub_port_connect drivers/usb/core/hub.c:5129 [inline]
>     [<ffffffff82b98441>] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline]
>     [<ffffffff82b98441>] port_event drivers/usb/core/hub.c:5509 [inline]
>     [<ffffffff82b98441>] hub_event+0x1171/0x20c0 drivers/usb/core/hub.c:5591
>     [<ffffffff81259229>] process_one_work+0x2c9/0x600 kernel/workqueue.c:2275
>     [<ffffffff81259b19>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2421
>     [<ffffffff81261228>] kthread+0x178/0x1b0 kernel/kthread.c:292
>     [<ffffffff8100227f>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
> 
> Reported-by: syzbot+636c58f40a86b4a879e7@syzkaller.appspotmail.com
> Fixes: 0f36163d3abe ("usb: fix uss720 schedule with interrupts off")
> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> ---
>  drivers/usb/misc/uss720.c | 1 +
>  1 file changed, 1 insertion(+)

What changed from v1?  That always goes below the --- line.

Please fix and send a v3.

thanks,

greg k-h

Re: [PATCH v2] misc/uss720: fix memory leak in uss720_probe

[慕冬亮]

On Fri, May 14, 2021 at 8:36 PM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Fri, May 14, 2021 at 08:34:25PM +0800, Dongliang Mu wrote:
> > uss720_probe forgets to decrease the refcount of usbdev in uss720_probe.
> > Fix this by decreasing the refcount of usbdev by usb_put_dev.
> >
> > BUG: memory leak
> > unreferenced object 0xffff888101113800 (size 2048):
> >   comm "kworker/0:1", pid 7, jiffies 4294956777 (age 28.870s)
> >   hex dump (first 32 bytes):
> >     ff ff ff ff 31 00 00 00 00 00 00 00 00 00 00 00  ....1...........
> >     00 00 00 00 00 00 00 00 00 00 00 00 03 00 00 00  ................
> >   backtrace:
> >     [<ffffffff82b8e822>] kmalloc include/linux/slab.h:554 [inline]
> >     [<ffffffff82b8e822>] kzalloc include/linux/slab.h:684 [inline]
> >     [<ffffffff82b8e822>] usb_alloc_dev+0x32/0x450 drivers/usb/core/usb.c:582
> >     [<ffffffff82b98441>] hub_port_connect drivers/usb/core/hub.c:5129 [inline]
> >     [<ffffffff82b98441>] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline]
> >     [<ffffffff82b98441>] port_event drivers/usb/core/hub.c:5509 [inline]
> >     [<ffffffff82b98441>] hub_event+0x1171/0x20c0 drivers/usb/core/hub.c:5591
> >     [<ffffffff81259229>] process_one_work+0x2c9/0x600 kernel/workqueue.c:2275
> >     [<ffffffff81259b19>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2421
> >     [<ffffffff81261228>] kthread+0x178/0x1b0 kernel/kthread.c:292
> >     [<ffffffff8100227f>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
> >
> > Reported-by: syzbot+636c58f40a86b4a879e7@syzkaller.appspotmail.com
> > Fixes: 0f36163d3abe ("usb: fix uss720 schedule with interrupts off")
> > Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> > ---
> >  drivers/usb/misc/uss720.c | 1 +
> >  1 file changed, 1 insertion(+)
>
> What changed from v1?  That always goes below the --- line.
>

I just added the Fixes tag as we discussed. "That" means what? The changes?

> Please fix and send a v3.
>
> thanks,
>
> greg k-h