Re: INFO: rcu detected stall in vprintk_func

[Dmitry Vyukov]

On Mon, Apr 2, 2018 at 4:04 AM, Sergey Senozhatsky
<sergey.senozhatsky.work@xxxxxxxxx> wrote:
> On (04/02/18 10:54), Sergey Senozhatsky wrote:
>> > > If you forward the report, please keep this part and the footer.
>> > >
>> > > llcp: nfc_llcp_send_ui_frame: Could not allocate PDU
>> > > llcp: nfc_llcp_send_ui_frame: Could not allocate PDU
>> > > llcp: nfc_llcp_send_ui_frame: Could not allocate PDU
>> > > llcp: nfc_llcp_send_ui_frame: Could not allocate PDU
>
> [..]
>
>> diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c
>> index ef4026a23e80..a309a27581da 100644
>> --- a/net/nfc/llcp_core.c
>> +++ b/net/nfc/llcp_core.c
>> @@ -1386,7 +1386,7 @@ static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
>>
>>               new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL);
>>               if (new_skb == NULL) {
>> -                     pr_err("Could not allocate PDU\n");
>> +                     pr_err_ratelimited("Could not allocate PDU\n");
>>                       return;
>>               }
>
> And of course I ended up patching the wrong function...
> What I actually meant was:
>
> ---
>
> diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c
> index 2ceefa183cee..2f3becb709b8 100644
> --- a/net/nfc/llcp_commands.c
> +++ b/net/nfc/llcp_commands.c
> @@ -755,7 +755,7 @@ int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
>                 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
>                                          frag_len + LLCP_HEADER_SIZE, &err);
>                 if (pdu == NULL) {
> -                       pr_err("Could not allocate PDU\n");
> +                       pr_err_ratelimited("Could not allocate PDU\n");
>                         continue;
>                 }
>


This is a duplicate of:

https://syzkaller.appspot.com/bug?id=ff33bd26f9147a02c60039098b063219df1ac131

#syz dup: INFO: rcu detected stall in llcp_sock_sendmsg