Re: KASAN: use-after-free Read in cpia2_usb_disconnect

From: Oliver Neukum
Date: Wed Jul 03 2019 - 03:56:07 EST


Am Dienstag, den 02.07.2019, 18:01 -0700 schrieb syzbot:
> syzbot has found a reproducer for the following crash on:
>
> HEAD commit: 7829a896 usb-fuzzer: main usb gadget fuzzer driver
> git tree: https://github.com/google/kasan.git usb-fuzzer
> console output: https://syzkaller.appspot.com/x/log.txt?x=11e19043a00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=f6d4561982f71f63
> dashboard link: https://syzkaller.appspot.com/bug?extid=0c90fc937c84f97d0aa6
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=147d42eda00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=104c268ba00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+0c90fc937c84f97d0aa6@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> cpia2: Message: count = 1, register[0] = 0x0
> cpia2: Unexpected error: -19
> ==================================================================
> BUG: KASAN: use-after-free in cpia2_usb_disconnect+0x1a4/0x1c0
> drivers/media/usb/cpia2/cpia2_usb.c:898
> Read of size 8 at addr ffff8881cf6c4e50 by task kworker/1:1/22

Please try this: