net/smc: Keep smc_close_final rc during active close

BugLink: https://bugs.launchpad.net/bugs/1953731
commit 00e158fb91dfaff3f94746f260d11f1a4853506e upstream.

When smc_close_final() returns error, the return code overwrites by
kernel_sock_shutdown() in smc_close_active(). The return code of
smc_close_final() is more important than kernel_sock_shutdown(), and it
will pass to userspace directly.

Fix it by keeping both return codes, if smc_close_final() raises an
error, return it or kernel_sock_shutdown()'s.

Link: https://lore.kernel.org/linux-s390/1f67548e-cbf6-0dce-82b5-10288a4583bd@linux.ibm.com/
Fixes: 606a63c9783a ("net/smc: Ensure the active closing peer first closes clcsock")
Suggested-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c
index 04620b53b74a79f0303ec9dfffa34ff0b6b11829..84102db5bb31452ed1e8aec94514418e4741d464 100644 (file)
--- a/net/smc/smc_close.c
+++ b/net/smc/smc_close.c
@@ -195,6 +195,7 @@ int smc_close_active(struct smc_sock *smc)
        int old_state;
        long timeout;
        int rc = 0;
+       int rc1 = 0;
 
        timeout = current->flags & PF_EXITING ?
                  0 : sock_flag(sk, SOCK_LINGER) ?
@@ -232,8 +233,11 @@ again:
                        /* actively shutdown clcsock before peer close it,
                         * prevent peer from entering TIME_WAIT state.
                         */
-                       if (smc->clcsock && smc->clcsock->sk)
-                               rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
+                       if (smc->clcsock && smc->clcsock->sk) {
+                               rc1 = kernel_sock_shutdown(smc->clcsock,
+                                                          SHUT_RDWR);
+                               rc = rc ? rc : rc1;
+                       }
                } else {
                        /* peer event has changed the state */
                        goto again;