On Fr, 2019-04-12 at 04:46 -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 9a33b369 usb-fuzzer: main usb gadget fuzzer driver > git tree: https://github.com/google/kasan/tree/usb-fuzzer > console output: https://syzkaller.appspot.com/x/log.txt?x=1643974b200000 > kernel config: https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15 > dashboard link: https://syzkaller.appspot.com/bug?extid=26ec41e9f788b3eba396 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12f5efa7200000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1395a0f3200000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+26ec41e9f788b3eba396@xxxxxxxxxxxxxxxxxxxxxxxxx > > dvb-usb: schedule remote query interval to 150 msecs. > dw2102: su3000_power_ctrl: 0, initialized 1 > dvb-usb: TeVii S421 PCI successfully initialized and connected. > usb 1-1: USB disconnect, device number 2 Hi, proposed fix. If nobody objects, I will submit it. Regards Oliver >From d6097d205ac61745334b79639d3b8b910ae66c71 Mon Sep 17 00:00:00 2001 From: Oliver Neukum <oneukum@xxxxxxxx> Date: Mon, 15 Apr 2019 13:06:01 +0200 Subject: [PATCH] dvb: usb: fix use after free in dvb_usb_device_exit dvb_usb_device_exit() frees and uses teh device name in that order Fix by storing the name in a buffer before freeing it Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx> Reported-by: syzbot+26ec41e9f788b3eba396@xxxxxxxxxxxxxxxxxxxxxxxxx --- drivers/media/usb/dvb-usb/dvb-usb-init.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c index 99951e02a880..2e1670cc3903 100644 --- a/drivers/media/usb/dvb-usb/dvb-usb-init.c +++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c @@ -288,13 +288,18 @@ void dvb_usb_device_exit(struct usb_interface *intf) { struct dvb_usb_device *d = usb_get_intfdata(intf); const char *name = "generic DVB-USB module"; + char identifier[40]; usb_set_intfdata(intf, NULL); if (d != NULL && d->desc != NULL) { name = d->desc->name; + memcpy(identifier, name, 39); + identifier[39] = NULL; dvb_usb_exit(d); + } else { + memcpy(identifier, name, 39); } - info("%s successfully deinitialized and disconnected.", name); + info("%s successfully deinitialized and disconnected.", identifier); } EXPORT_SYMBOL(dvb_usb_device_exit); -- 2.16.4
