libtirpc: CVE-2021-46828 DoS vulnerability with lots of connections

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>

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 (file)
index 0000000..c78e7ef
--- /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 10a324c3b6a485364325e319777906c575d00661..fe4e30e61f95db4a59a551829305a79568b1a5fb 100644 (file)
--- 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"