4.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ursula Braun <ubraun@xxxxxxxxxxxxxxxxxx>
[ Upstream commit 1255fcb2a655f05e02f3a74675a6d6525f187afd ]
Calling shutdown with SHUT_RD and SHUT_RDWR for a listening SMC socket
crashes, because
commit 127f49705823 ("net/smc: release clcsock from tcp_listen_worker")
releases the internal clcsock in smc_close_active() and sets smc->clcsock
to NULL.
For SHUT_RD the smc_close_active() call is removed.
For SHUT_RDWR the kernel_sock_shutdown() call is omitted, since the
clcsock is already released.
Fixes: 127f49705823 ("net/smc: release clcsock from tcp_listen_worker")
Signed-off-by: Ursula Braun <ubraun@xxxxxxxxxxxxxxxxxx>
Reported-by: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/smc/af_smc.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1254,14 +1254,12 @@ static int smc_shutdown(struct socket *s
rc = smc_close_shutdown_write(smc);
break;
case SHUT_RD:
- if (sk->sk_state == SMC_LISTEN)
- rc = smc_close_active(smc);
- else
- rc = 0;
- /* nothing more to do because peer is not involved */
+ rc = 0;
+ /* nothing more to do because peer is not involved */
break;
}
- rc1 = kernel_sock_shutdown(smc->clcsock, how);
+ if (smc->clcsock)
+ rc1 = kernel_sock_shutdown(smc->clcsock, how);
/* map sock_shutdown_cmd constants to sk_shutdown value range */
sk->sk_shutdown |= how + 1;