From 48309e7cb230fc539c3edab0b3363f8ce973194f Mon Sep 17 00:00:00 2001
From: Hitendra Prajapati <hprajapati@mvista.com>
Date: Thu, 28 Jul 2022 09:11:04 +0530
Subject: [PATCH] CVE-2021-46828
Upstream-Status: Backport [http://git.linux-nfs.org/?p=steved/libtirpc.git;a=commit;h=86529758570cef4c73fb9b9c4104fdc510f701ed}
CVE: CVE-2021-46828
Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
---
src/svc.c | 17 +++++++++++++-
src/svc_vc.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 77 insertions(+), 2 deletions(-)
diff --git a/src/svc.c b/src/svc.c
index 6db164b..3a8709f 100644
--- a/src/svc.c
+++ b/src/svc.c
@@ -57,7 +57,7 @@
#define max(a, b) (a > b ? a : b)
-static SVCXPRT **__svc_xports;
+SVCXPRT **__svc_xports;
int __svc_maxrec;
/*
@@ -194,6 +194,21 @@ __xprt_do_unregister (xprt, dolock)
rwlock_unlock (&svc_fd_lock);
}
+int
+svc_open_fds()
+{
+ int ix;
+ int nfds = 0;
+
+ rwlock_rdlock (&svc_fd_lock);
+ for (ix = 0; ix < svc_max_pollfd; ++ix) {
+ if (svc_pollfd[ix].fd != -1)
+ nfds++;
+ }
+ rwlock_unlock (&svc_fd_lock);
+ return (nfds);
+}
+
/*
* Add a service program to the callout list.
* The dispatch routine will be called when a rpc request for this
diff --git a/src/svc_vc.c b/src/svc_vc.c
index c23cd36..1729963 100644
--- a/src/svc_vc.c
+++ b/src/svc_vc.c
@@ -64,6 +64,8 @@
extern rwlock_t svc_fd_lock;
+extern SVCXPRT **__svc_xports;
+extern int svc_open_fds();
static SVCXPRT *makefd_xprt(int, u_int, u_int);
static bool_t rendezvous_request(SVCXPRT *, struct rpc_msg *);
@@ -82,6 +84,7 @@ static void svc_vc_ops(SVCXPRT *);
static bool_t svc_vc_control(SVCXPRT *xprt, const u_int rq, void *in);
static bool_t svc_vc_rendezvous_control (SVCXPRT *xprt, const u_int rq,
void *in);
+static int __svc_destroy_idle(int timeout);
struct cf_rendezvous { /* kept in xprt->xp_p1 for rendezvouser */
u_int sendsize;
@@ -312,13 +315,14 @@ done:
return (xprt);
}
+
/*ARGSUSED*/
static bool_t
rendezvous_request(xprt, msg)
SVCXPRT *xprt;
struct rpc_msg *msg;
{
- int sock, flags;
+ int sock, flags, nfds, cnt;
struct cf_rendezvous *r;
struct cf_conn *cd;
struct sockaddr_storage addr;
@@ -378,6 +382,16 @@ again:
gettimeofday(&cd->last_recv_time, NULL);
+ nfds = svc_open_fds();
+ if (nfds >= (_rpc_dtablesize() / 5) * 4) {
+ /* destroy idle connections */
+ cnt = __svc_destroy_idle(15);
+ if (cnt == 0) {
+ /* destroy least active */
+ __svc_destroy_idle(0);
+ }
+ }
+
return (FALSE); /* there is never an rpc msg to be processed */
}
@@ -819,3 +833,49 @@ __svc_clean_idle(fd_set *fds, int timeout, bool_t cleanblock)
{
return FALSE;
}
+
+static int
+__svc_destroy_idle(int timeout)
+{
+ int i, ncleaned = 0;
+ SVCXPRT *xprt, *least_active;
+ struct timeval tv, tdiff, tmax;
+ struct cf_conn *cd;
+
+ gettimeofday(&tv, NULL);
+ tmax.tv_sec = tmax.tv_usec = 0;
+ least_active = NULL;
+ rwlock_wrlock(&svc_fd_lock);
+
+ for (i = 0; i <= svc_max_pollfd; i++) {
+ if (svc_pollfd[i].fd == -1)
+ continue;
+ xprt = __svc_xports[i];
+ if (xprt == NULL || xprt->xp_ops == NULL ||
+ xprt->xp_ops->xp_recv != svc_vc_recv)
+ continue;
+ cd = (struct cf_conn *)xprt->xp_p1;
+ if (!cd->nonblock)
+ continue;
+ if (timeout == 0) {
+ timersub(&tv, &cd->last_recv_time, &tdiff);
+ if (timercmp(&tdiff, &tmax, >)) {
+ tmax = tdiff;
+ least_active = xprt;
+ }
+ continue;
+ }
+ if (tv.tv_sec - cd->last_recv_time.tv_sec > timeout) {
+ __xprt_unregister_unlocked(xprt);
+ __svc_vc_dodestroy(xprt);
+ ncleaned++;
+ }
+ }
+ if (timeout == 0 && least_active != NULL) {
+ __xprt_unregister_unlocked(least_active);
+ __svc_vc_dodestroy(least_active);
+ ncleaned++;
+ }
+ rwlock_unlock(&svc_fd_lock);
+ return (ncleaned);
+}
--
2.25.1