On Fri, Nov 20, 2020 at 07:15:20AM -0800, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 4d02da97 Merge tag 'net-5.10-rc5' of git://git.kernel.org/.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=13a7d2b6500000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c5353ac514ca5a43 > dashboard link: https://syzkaller.appspot.com/bug?extid=44e64397bd81d5e84cba > compiler: gcc (GCC) 10.1.0-syz 20200507 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14925089500000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16810051500000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+44e64397bd81d5e84cba@xxxxxxxxxxxxxxxxxxxxxxxxx > > BUG: memory leak > unreferenced object 0xffff88810d5ff800 (size 2048): > comm "kworker/1:0", pid 17, jiffies 4294949188 (age 14.280s) > 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: > [<00000000f0428224>] kmalloc include/linux/slab.h:552 [inline] > [<00000000f0428224>] kzalloc include/linux/slab.h:664 [inline] > [<00000000f0428224>] usb_alloc_dev+0x32/0x450 drivers/usb/core/usb.c:582 > [<000000001802b3dd>] hub_port_connect drivers/usb/core/hub.c:5128 [inline] > [<000000001802b3dd>] hub_port_connect_change drivers/usb/core/hub.c:5362 [inline] > [<000000001802b3dd>] port_event drivers/usb/core/hub.c:5508 [inline] > [<000000001802b3dd>] hub_event+0x118d/0x20d0 drivers/usb/core/hub.c:5590 > [<0000000092d3650d>] process_one_work+0x27d/0x590 kernel/workqueue.c:2272 > [<00000000d4629ab0>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2418 > [<000000003c358b45>] kthread+0x178/0x1b0 kernel/kthread.c:292 > [<000000003689dbb0>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 This looks like a reference is being taken but not released. Hard to tell where it's happening, though. Let's try to narrow it down. Alan Stern #syz test: upstream 4d02da97 Index: usb-devel/drivers/media/usb/gspca/gspca.c =================================================================== --- usb-devel.orig/drivers/media/usb/gspca/gspca.c +++ usb-devel/drivers/media/usb/gspca/gspca.c @@ -1489,6 +1489,8 @@ int gspca_dev_probe2(struct usb_interfac } gspca_dev->v4l2_dev.release = gspca_release; + ret = -EIO; + goto out; ret = v4l2_device_register(&intf->dev, &gspca_dev->v4l2_dev); if (ret) goto out;
