[PATCH 4.19 51/57] usb: gadget: f_midi: Fix memleak in f_midi_alloc

[Greg Kroah-Hartman]

From: Zhang Qilong <zhangqilo...@huawei.com>

commit e7694cb6998379341fd9bf3bd62b48c4e6a79385 upstream.

In the error path, if midi is not null, we should
free the midi->id if necessary to prevent memleak.

Fixes: b85e9de9e818d ("usb: gadget: f_midi: convert to new function interface 
with backward compatibility")
Reported-by: Hulk Robot <hul...@huawei.com>
Signed-off-by: Zhang Qilong <zhangqilo...@huawei.com>
Link: https://lore.kernel.org/r/20201117021629.1470544-2-zhangqilo...@huawei.com
Cc: stable <sta...@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/usb/gadget/function/f_midi.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

--- a/drivers/usb/gadget/function/f_midi.c
+++ b/drivers/usb/gadget/function/f_midi.c
@@ -1315,7 +1315,7 @@ static struct usb_function *f_midi_alloc
        midi->id = kstrdup(opts->id, GFP_KERNEL);
        if (opts->id && !midi->id) {
                status = -ENOMEM;
-               goto setup_fail;
+               goto midi_free;
        }
        midi->in_ports = opts->in_ports;
        midi->out_ports = opts->out_ports;
@@ -1327,7 +1327,7 @@ static struct usb_function *f_midi_alloc
 
        status = kfifo_alloc(&midi->in_req_fifo, midi->qlen, GFP_KERNEL);
        if (status)
-               goto setup_fail;
+               goto midi_free;
 
        spin_lock_init(&midi->transmit_lock);
 
@@ -1343,9 +1343,13 @@ static struct usb_function *f_midi_alloc
 
        return &midi->func;
 
+midi_free:
+       if (midi)
+               kfree(midi->id);
+       kfree(midi);
 setup_fail:
        mutex_unlock(&opts->lock);
-       kfree(midi);
+
        return ERR_PTR(status);
 }