Since commit e5d5aadcf3cd ("net/smc: fix sk_refcnt underflow on linkdown and fallback"), for a fallback connection, __smc_release() does not call sock_put() if its state is already SMC_CLOSED. When calling smc_shutdown() after falling back, its state is set to SMC_CLOSED but does not call sock_put(), so this patch calls it. Reported-and-tested-by: syzbot+6e29a053eb165bd50de5@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: e5d5aadcf3cd ("net/smc: fix sk_refcnt underflow on linkdown and fallback") Signed-off-by: Tony Lu <tonylu@xxxxxxxxxxxxxxxxx> --- net/smc/af_smc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index f0d118e9f155..f842425da6ec 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -2664,8 +2664,10 @@ static int smc_shutdown(struct socket *sock, int how) if (smc->use_fallback) { rc = kernel_sock_shutdown(smc->clcsock, how); sk->sk_shutdown = smc->clcsock->sk->sk_shutdown; - if (sk->sk_shutdown == SHUTDOWN_MASK) + if (sk->sk_shutdown == SHUTDOWN_MASK) { sk->sk_state = SMC_CLOSED; + sock_put(sk); + } goto out; } switch (how) { -- 2.32.0.3.g01195cf9f