[OE-core][dunfell 7/7] libtirpc: CVE-2021-46828 DoS vulnerability with lots of connections

[Steve Sakoman <steve@sakoman.com>]

From: Hitendra Prajapati <hprajapati@mvista.com>

Source: http://git.linux-nfs.org/?p=steved/libtirpc.git;
MR: 120231
Type: Security Fix
Disposition: Backport from http://git.linux-nfs.org/?p=steved/libtirpc.git;a=commit;h=86529758570cef4c73fb9b9c4104fdc510f701ed
ChangeID: 544120a5f10a4717cd2c7291821a012e26b14b7f
Description:
        CVE-2021-46828 libtirpc: DoS vulnerability with lots of connections.

Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
---
 .../libtirpc/libtirpc/CVE-2021-46828.patch    | 155 ++++++++++++++++++
 .../libtirpc/libtirpc_1.2.6.bb                |   4 +-
 2 files changed, 158 insertions(+), 1 deletion(-)
 create mode 100644 meta/recipes-extended/libtirpc/libtirpc/CVE-2021-46828.patch

diff --git a/meta/recipes-extended/libtirpc/libtirpc/CVE-2021-46828.patch b/meta/recipes-extended/libtirpc/libtirpc/CVE-2021-46828.patch
new file mode 100644
index 0000000000..c78e7ef4d5
--- /dev/null
+++ b/meta/recipes-extended/libtirpc/libtirpc/CVE-2021-46828.patch
@@ -0,0 +1,155 @@
+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
+
diff --git a/meta/recipes-extended/libtirpc/libtirpc_1.2.6.bb b/meta/recipes-extended/libtirpc/libtirpc_1.2.6.bb
index 10a324c3b6..fe4e30e61f 100644
--- a/meta/recipes-extended/libtirpc/libtirpc_1.2.6.bb
+++ b/meta/recipes-extended/libtirpc/libtirpc_1.2.6.bb
@@ -9,7 +9,9 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=f835cce8852481e4b2bbbdd23b5e47f3 \
 
 PROVIDES = "virtual/librpc"
 
-SRC_URI = "${SOURCEFORGE_MIRROR}/${BPN}/${BP}.tar.bz2"
+SRC_URI = "${SOURCEFORGE_MIRROR}/${BPN}/${BP}.tar.bz2 \
+	   file://CVE-2021-46828.patch \
+	  "
 UPSTREAM_CHECK_URI = "https://sourceforge.net/projects/libtirpc/files/libtirpc/"
 UPSTREAM_CHECK_REGEX = "(?P<pver>\d+(\.\d+)+)/"
 SRC_URI[md5sum] = "b25f9cc18bfad50f7c446c77f4ae00bb"
-- 
2.25.1