Date:   Mon, 06 Dec 2021 11:02:42 -0800
From:   John Fastabend <john.fastabend@gmail.com>
To:     syzbot <syzbot+5027de09e0964fd78ce1@syzkaller.appspotmail.com>,
        andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org,
        daniel@iogearbox.net, davem@davemloft.net, hawk@kernel.org,
        john.fastabend@gmail.com, kafai@fb.com, kpsingh@kernel.org,
        kuba@kernel.org, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, songliubraving@fb.com,
        syzkaller-bugs@googlegroups.com, yhs@fb.com
Message-ID: <61ae5e52b9712_c5bd2082e@john.notmuch>
In-Reply-To: <000000000000367c2205d2549cb9@google.com>
References: <000000000000367c2205d2549cb9@google.com>
Subject: RE: [syzbot] KASAN: vmalloc-out-of-bounds Read in __bpf_prog_put
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syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    ce83278f313c Merge branch 'qed-enhancements'
> git tree:       net-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=11c8ce3ab00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=b5949d4891208a1b
> dashboard link: https://syzkaller.appspot.com/bug?extid=5027de09e0964fd78ce1
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+5027de09e0964fd78ce1@syzkaller.appspotmail.com
> 
> ==================================================================
> BUG: KASAN: vmalloc-out-of-bounds in __bpf_prog_put.constprop.0+0x1dd/0x220 kernel/bpf/syscall.c:1812
> Read of size 8 at addr ffffc90000cf2038 by task kworker/0:24/16179
> 
> CPU: 0 PID: 16179 Comm: kworker/0:24 Not tainted 5.16.0-rc3-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events sk_psock_destroy
> Call Trace:
>  <TASK>
>  __dump_stack lib/dump_stack.c:88 [inline]
>  dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
>  print_address_description.constprop.0.cold+0xf/0x320 mm/kasan/report.c:247
>  __kasan_report mm/kasan/report.c:433 [inline]
>  kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
>  __bpf_prog_put.constprop.0+0x1dd/0x220 kernel/bpf/syscall.c:1812
>  psock_set_prog include/linux/skmsg.h:477 [inline]
>  psock_progs_drop include/linux/skmsg.h:495 [inline]
>  sk_psock_destroy+0xad/0x620 net/core/skmsg.c:804
>  process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
>  worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
>  kthread+0x405/0x4f0 kernel/kthread.c:327
>  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
>  </TASK>
> 
> 
> Memory state around the buggy address:
>  ffffc90000cf1f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>  ffffc90000cf1f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
> >ffffc90000cf2000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>                                         ^
>  ffffc90000cf2080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>  ffffc90000cf2100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
> ==================================================================
> 
> 
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
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I'll take look some psock issue here.