Re: WARNING in handle_irq (3)

[John Fastabend]

On 08/30/2018 08:39 AM, Dmitry Vyukov wrote:
> On Thu, Aug 30, 2018 at 8:31 AM, syzbot
> <syzbot+a58b558e3e62d0604e5c@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>> Hello,
>>
>> syzbot found the following crash on:
>>
>> HEAD commit:    58c3f14f86c9 Merge tag 'riscv-for-linus-4.19-rc2' of git:/..
>> git tree:       upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=10be176a400000
>> kernel config:  https://syzkaller.appspot.com/x/.config?x=531a917630d2a492
>> dashboard link: https://syzkaller.appspot.com/bug?extid=a58b558e3e62d0604e5c
>> compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
>>
>> Unfortunately, I don't have any reproducer for this crash yet.
> 
> +bpf maintainers
> 
> Looks suspiciously similar to:
> https://groups.google.com/d/msg/syzkaller-bugs/4v7MtbIT1hY/A87hInzyAwAJ
> 
> Note this commit seems to already have "bpf, sockmap: fix
> sock_hash_alloc and reject zero-sized keys ".
> 
> Tentative reproducer from the log is:
> 
> 14:08:59 executing program 5:
> socketpair(0x20000, 0x0, 0x0, &(0x7f0000000140))
> r0 = socket$inet6_tcp(0xa, 0x1, 0x0)
> r1 = socket$inet6_tcp(0xa, 0x1, 0x0)
> bind$inet6(r1, &(0x7f00000000c0)={0xa, 0x4e22}, 0x1c)
> listen(r1, 0x0)
> sendto$inet6(r0, &(0x7f0000000140), 0x2d6, 0x20000004,
> &(0x7f0000000080)={0xa, 0x100000004e22, 0x0, @loopback}, 0x1c)
> setsockopt$inet6_tcp_TCP_ULP(r0, 0x6, 0x1f, &(0x7f0000000080)='tls\x00', 0x152)
> r2 = bpf$MAP_CREATE(0x0, &(0x7f0000000280)={0xf, 0x4, 0x4, 0x70}, 0x2c)
> bpf$MAP_UPDATE_ELEM(0x2, &(0x7f0000000180)={r2, &(0x7f0000000000),
> &(0x7f0000000140)}, 0x20)
> 
> Which does not create a 0-key map.
> 
> 

Hi Dmitry,

Testing a fix for this now, we have an error path that can
call module_put and/or null the ulp ops erroneously. Should
have something out later tonight or worst case early tomorrow.
Thanks for the snippet.

Thanks,
John