From: Tony Lu tonylu@linux.alibaba.com
[ Upstream commit 1a74e99323746353bba11562a2f2d0aa8102f402 ]
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@syzkaller.appspotmail.com Fixes: e5d5aadcf3cd ("net/smc: fix sk_refcnt underflow on linkdown and fallback") Signed-off-by: Tony Lu tonylu@linux.alibaba.com Acked-by: Karsten Graul kgraul@linux.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 303c5e56e4df..68cd110722a4 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -2538,8 +2538,10 @@ 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) {