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Date:   Wed, 24 Mar 2021 23:07:53 +0500
From:   Muhammad Usama Anjum <musamaanjum@gmail.com>
To:     linux-kernel@vger.kernel.org,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        "open list:EM28XX VIDEO4LINUX DRIVER" <linux-media@vger.kernel.org>
Cc:     musamaanjum@gmail.com, syzkaller-bugs@googlegroups.com,
        dvyukov@google.com
Subject: [PATCH] media: em28xx: fix memory leak
Message-ID: <20210324180753.GA410359@LEGION>
MIME-Version: 1.0
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If some error occurs, URB buffers should also be freed. If they aren't
freed with the dvb here, the em28xx_dvb_fini call doesn't frees the URB
buffers as dvb is set to NULL. The function in which error occurs should
do all the cleanup for the allocations it had done.

Tested the patch with the reproducer provided by syzbot. This patch
fixes the memleak.

Reported-by: syzbot+889397c820fa56adf25d@syzkaller.appspotmail.com
Signed-off-by: Muhammad Usama Anjum <musamaanjum@gmail.com>
---
Resending the same path as some email addresses were missing from the
earlier email.

syzbot found the following issue on:

HEAD commit:    1a4431a5 Merge tag 'afs-fixes-20210315' of git://git.kerne..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11013a7cd00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ff6b8b2e9d5a1227
dashboard link: https://syzkaller.appspot.com/bug?extid=889397c820fa56adf25d
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1559ae3ad00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=176985c6d00000

 drivers/media/usb/em28xx/em28xx-dvb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/media/usb/em28xx/em28xx-dvb.c b/drivers/media/usb/em28xx/em28xx-dvb.c
index 526424279637..471bd74667e3 100644
--- a/drivers/media/usb/em28xx/em28xx-dvb.c
+++ b/drivers/media/usb/em28xx/em28xx-dvb.c
@@ -2010,6 +2010,7 @@ static int em28xx_dvb_init(struct em28xx *dev)
 	return result;
 
 out_free:
+	em28xx_uninit_usb_xfer(dev, EM28XX_DIGITAL_MODE);
 	kfree(dvb);
 	dev->dvb = NULL;
 	goto ret;
-- 
2.25.1