From: Karsten Graul <kgraul@xxxxxxxxxxxxx>
Date: Fri, 15 Nov 2019 12:39:30 +0100
> From: Ursula Braun <ubraun@xxxxxxxxxxxxx>
>
> FASTOPEN does not work with SMC-sockets. Since SMC allows fallback to
> TCP native during connection start, the FASTOPEN setsockopts trigger
> this fallback, if the SMC-socket is still in state SMC_INIT.
> But if a FASTOPEN setsockopt is called after a non-blocking connect(),
> this is broken, and fallback does not make sense.
> This change complements
> commit cd2063604ea6 ("net/smc: avoid fallback in case of non-blocking connect")
> and fixes the syzbot reported problem "WARNING in smc_unhash_sk".
>
> Reported-by: syzbot+8488cc4cf1c9e09b8b86@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: e1bbdd570474 ("net/smc: reduce sock_put() for fallback sockets")
> Signed-off-by: Ursula Braun <ubraun@xxxxxxxxxxxxx>
> Signed-off-by: Karsten Graul <kgraul@xxxxxxxxxxxxx>
Applied and queued up for -stable, thanks.
