Re: [PATCH net 1/5] net/smc: fix dangling sock under state SMC_APPFINCLOSEWAIT

Wenjia Zhang
2023-10-23T20:53:40Z

On 11.10.23 09:33, D. Wythe wrote:
> From: "D. Wythe" <alibuda@linux.alibaba.com>
>
> Considering scenario:
>
> smc_cdc_rx_handler_rwwi
> __smc_release
> sock_set_flag
> smc_close_active()
> sock_set_flag
>
> __set_bit(DEAD) __set_bit(DONE)
>
> Dues to __set_bit is not atomic, the DEAD or DONE might be lost.
> if the DEAD flag lost, the state SMC_CLOSED will be never be reached
> in smc_close_passive_work:
>
> if (sock_flag(sk, SOCK_DEAD) &&
> smc_close_sent_any_close(conn)) {
> sk->sk_state = SMC_CLOSED;
> } else {
> /* just shutdown, but not yet closed locally */
> sk->sk_state = SMC_APPFINCLOSEWAIT;
> }
>
> Replace sock_set_flags or __set_bit to set_bit will fix this problem.
> Since set_bit is atomic.
>
> Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
> ---
> net/smc/af_smc.c | 4 ++--
> net/smc/smc.h | 5 +++++
> net/smc/smc_cdc.c | 2 +-
> net/smc/smc_close.c | 2 +-
> 4 files changed, 9 insertions(+), 4 deletions(-)
>

Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>