sunrpc: expiry_time should be seconds not timeval

stable inclusion
from linux-4.19.103
commit a90c2c5e8c01c50b6ba026742d0bfd3299b42d26

--------------------------------

commit 3d96208c upstream.

When upcalling gssproxy, cache_head.expiry_time is set as a
timeval, not seconds since boot. As such, RPC cache expiry
logic will not clean expired objects created under
auth.rpcsec.context cache.

This has proven to cause kernel memory leaks on field. Using
64 bit variants of getboottime/timespec

Expiration times have worked this way since 2010's c5b29f88 "sunrpc:
use seconds since boot in expiry cache".  The gssproxy code introduced
in 2012 added gss_proxy_save_rsc and introduced the bug.  That's a while
for this to lurk, but it required a bit of an extreme case to make it
obvious.
Signed-off-by: NRoberto Bergantinos Corpas <rbergant@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 030d794b "SUNRPC: Use gssproxy upcall for server..."
Tested-By: NFrank Sorenson <sorenson@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NLi Aichun <liaichun@huawei.com>
Reviewed-by: Nguodeqing <geffrey.guo@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

net/sunrpc/auth_gss/svcauth_gss.c

@@ -1192,6 +1192,7 @@ static int gss_proxy_save_rsc(struct cache_detail *cd,
 		dprintk("RPC:       No creds found!\n");
 		goto out;
 	} else {
+		struct timespec64 boot;
 
 		/* steal creds */
 		rsci.cred = ud->creds;
@@ -1212,6 +1213,9 @@ static int gss_proxy_save_rsc(struct cache_detail *cd,
 						&expiry, GFP_KERNEL);
 		if (status)
 			goto out;
+
+		getboottime64(&boot);
+		expiry -= boot.tv_sec;
 	}
 
 	rsci.h.expiry_time = expiry;