[PATCH 5.6 33/38] Bluetooth: RFCOMM: fix ODEBUG bug in rfcomm_dev_ioctl

Greg Kroah-Hartman
2020-04-11T12:21:43Z

From: Qiujun Huang <hqjagain@gmail.com>

commit 71811cac8532b2387b3414f7cd8fe9e497482864 upstream.

Needn't call 'rfcomm_dlc_put' here, because 'rfcomm_dlc_exists' didn't
increase dlc->refcnt.

Reported-by: syzbot+4496e82090657320efc6@syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Suggested-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/bluetooth/rfcomm/tty.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -413,10 +413,8 @@ static int __rfcomm_create_dev(struct so
dlc = rfcomm_dlc_exists(&req.src, &req.dst, req.channel);
if (IS_ERR(dlc))
return PTR_ERR(dlc);
- else if (dlc) {
- rfcomm_dlc_put(dlc);
+ if (dlc)
return -EBUSY;
- }
dlc = rfcomm_dlc_alloc(GFP_KERNEL);
if (!dlc)
return -ENOMEM;