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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Takashi Iwai <tiwai@suse.de>, Jaroslav Kysela <perex@perex.cz>
Subject: [PATCH 37/69] ALSA: usx2y: check for failure of usb_alloc_urb()
Date:   Mon,  3 May 2021 13:57:04 +0200
Message-Id: <20210503115736.2104747-38-gregkh@linuxfoundation.org>
In-Reply-To: <20210503115736.2104747-1-gregkh@linuxfoundation.org>
References: <20210503115736.2104747-1-gregkh@linuxfoundation.org>
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While it is almost impossible to hit an error calling usb_alloc_urb(),
to make systems like syzbot which does error injection, and some static
analysis tools happy, properly handle errors on this path by unwinding
the previously allocated urbs and freeing them.

Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 sound/usb/usx2y/usb_stream.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/sound/usb/usx2y/usb_stream.c b/sound/usb/usx2y/usb_stream.c
index 6bba17bf689a..1091ea96a29a 100644
--- a/sound/usb/usx2y/usb_stream.c
+++ b/sound/usb/usx2y/usb_stream.c
@@ -88,18 +88,35 @@ static int init_urbs(struct usb_stream_kernel *sk, unsigned use_packsize,
 					sizeof(struct usb_stream_packet) *
 					s->inpackets;
 	int			u;
+	int			i;
+	int			err = -ENOMEM;
 
 	for (u = 0; u < USB_STREAM_NURBS; ++u) {
+		sk->outurb[u] = NULL;
 		sk->inurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
+		if (!sk->inurb[u])
+			goto error;
 		sk->outurb[u] = usb_alloc_urb(sk->n_o_ps, GFP_KERNEL);
+		if (!sk->outurb[u])
+			goto error;
 	}
+	u--;
 
 	if (init_pipe_urbs(sk, use_packsize, sk->inurb, indata, dev, in_pipe) ||
 	    init_pipe_urbs(sk, use_packsize, sk->outurb, sk->write_page, dev,
-			   out_pipe))
-		return -EINVAL;
+			   out_pipe)) {
+		err = -EINVAL;
+		goto error;
+	}
 
 	return 0;
+
+error:
+	for (i = 0; i <= u; ++i) {
+		usb_free_urb(sk->inurb[i]);
+		usb_free_urb(sk->outurb[i]);
+	}
+	return err;
 }
 
 
-- 
2.31.1