Hi,

On Wed, Aug 03, 2022 at 04:17:43PM +0200, Salvatore Bonaccorso wrote:
> Hi Josue,
> 
> On Wed, Aug 03, 2022 at 07:42:33AM -0600, Josue Ortega wrote:
> > On Mon, Aug 01, 2022 at 09:55:07PM +0200, Salvatore Bonaccorso wrote:
> > > Control: tags 1015873 + patch
> > > Control: tags 1015873 + pending
> > > 
> > > 
> > > Dear maintainer,
> > > 
> > > I've prepared an NMU for libtirpc (versioned as 1.3.2-2.1) and
> > > uploaded it to DELAYED/5. Please feel free to tell me if I
> > > should delay it longer.
> > > 
> > > The corresponding merge request is at
> > > https://salsa.debian.org/debian/libtirpc/-/merge_requests/1 .
> > > 
> > > Regards,
> > > Salvatore
> > 
> > 
> > Hey Salvatore,
> > 
> > Thanks for working on this. My original plan was to work on the Stable patch
> > first and then work on the unstable solution. However, I couldn't find the
> > time to do it during this week. I'll be working in the stable patch over 
> > this
> > weekend. So, if you are so kind to delay the upload 5 more days, that would
> > be great.
> 
> In fact I have at same time as well already prepared the corresponding
> security update for bullseye-security and the packages are sitting in
> the embaroged queues on security-master. 
> 
> My aim was here to have the top-down approach instead, have the fix
> land in unstable, have some additional exposure and then only release
> the DSA.
> 
> The debdiff for stable is very similar and have as well done the
> changes in the git repository in a bullseye branch but not pushed it
> though.
> 
> Can attach the debdiff as well for reference if wanted.

Done here, attached the debdiff used for the security update.

Regards,
Salvatore
diff -Nru libtirpc-1.3.1/debian/changelog libtirpc-1.3.1/debian/changelog
--- libtirpc-1.3.1/debian/changelog     2020-12-31 02:21:05.000000000 +0100
+++ libtirpc-1.3.1/debian/changelog     2022-08-01 16:26:18.000000000 +0200
@@ -1,3 +1,10 @@
+libtirpc (1.3.1-1+deb11u1) bullseye-security; urgency=high
+
+  * Non-maintainer upload by the Security Team.
+  * Fix DoS vulnerability in libtirpc (CVE-2021-46828) (Closes: #1015873)
+
+ -- Salvatore Bonaccorso <car...@debian.org>  Mon, 01 Aug 2022 16:26:18 +0200
+
 libtirpc (1.3.1-1) unstable; urgency=medium
 
   * New upstream release (1.3.1):
diff -Nru libtirpc-1.3.1/debian/patches/Fix-DoS-vulnerability-in-libtirpc.patch 
libtirpc-1.3.1/debian/patches/Fix-DoS-vulnerability-in-libtirpc.patch
--- libtirpc-1.3.1/debian/patches/Fix-DoS-vulnerability-in-libtirpc.patch       
1970-01-01 01:00:00.000000000 +0100
+++ libtirpc-1.3.1/debian/patches/Fix-DoS-vulnerability-in-libtirpc.patch       
2022-08-01 16:26:18.000000000 +0200
@@ -0,0 +1,180 @@
+From: Dai Ngo <dai....@oracle.com>
+Date: Sat, 21 Aug 2021 13:16:23 -0400
+Subject: Fix DoS vulnerability in libtirpc
+Origin: 
http://git.linux-nfs.org/?p=steved/libtirpc.git;a=commit;h=86529758570cef4c73fb9b9c4104fdc510f701ed
+Bug-Debian: https://bugs.debian.org/1015873
+Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2021-46828
+
+Currently svc_run does not handle poll timeout and rendezvous_request
+does not handle EMFILE error returned from accept(2 as it used to.
+These two missing functionality were removed by commit b2c9430f46c4.
+
+The effect of not handling poll timeout allows idle TCP conections
+to remain ESTABLISHED indefinitely. When the number of connections
+reaches the limit of the open file descriptors (ulimit -n) then
+accept(2) fails with EMFILE. Since there is no handling of EMFILE
+error this causes svc_run() to get in a tight loop calling accept(2).
+This resulting in the RPC service of svc_run is being down, it's
+no longer able to service any requests.
+
+RPC service rpcbind, statd and mountd are effected by this
+problem.
+
+Fix by enhancing rendezvous_request to keep the number of
+SVCXPRT conections to 4/5 of the size of the file descriptor
+table. When this thresold is reached, it destroys the idle
+TCP connections or destroys the least active connection if
+no idle connnction was found.
+
+Fixes: 44bf15b8 rpcbind: don't use obsolete svc_fdset interface of libtirpc
+Signed-off-by: dai....@oracle.com
+Signed-off-by: Steve Dickson <ste...@redhat.com>
+---
+ INSTALL      | 371 +--------------------------------------------------
+ src/svc.c    |  17 ++-
+ src/svc_vc.c |  62 ++++++++-
+ 3 files changed, 78 insertions(+), 372 deletions(-)
+ mode change 100644 => 120000 INSTALL
+
+diff --git a/src/svc.c b/src/svc.c
+index 6db164bbd76b..3a8709fe375c 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 f1d9f001fcdc..3dc8a75787e1 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;
+@@ -313,13 +316,14 @@ 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;
+@@ -379,6 +383,16 @@ 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 */
+ }
+ 
+@@ -820,3 +834,49 @@ __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);
++}
+-- 
+2.36.1
+
diff -Nru libtirpc-1.3.1/debian/patches/series 
libtirpc-1.3.1/debian/patches/series
--- libtirpc-1.3.1/debian/patches/series        2020-12-31 02:21:05.000000000 
+0100
+++ libtirpc-1.3.1/debian/patches/series        2022-08-01 16:26:18.000000000 
+0200
@@ -1,3 +1,4 @@
 03-kfreebsd.diff
 05-hurd-port.diff
 06-hurd-client-port.diff
+Fix-DoS-vulnerability-in-libtirpc.patch

Reply via email to