rpcbind: Backport fixes to memory leak security fix

Commit 954509f added a security fix for CVE-2017-8779, involving
pairing all svc_getargs() calls with svc_freeargs() to avoid a memory
leak.  However it also introduced a couple of issues:

- The call to svc_freeargs() from rpcbproc_callit_com() may result in
  an attempt to free static memory, resulting in undefined behaviour.

- A typo in the svc_freeargs() call from pmapproc_dump() causes NIS
  (aka ypbind) to fail.

Backport upstream fixes for these issues to version 0.2.3.

Signed-off-by: Ed Blake <ed.blake@sondrel.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

diff --git a/package/rpcbind/0005-rpcbproc_callit_com-Stop-freeing-a-static-pointer.patch b/package/rpcbind/0005-rpcbproc_callit_com-Stop-freeing-a-static-pointer.patch
new file mode 100644 (file)
index 0000000..c482af5
--- /dev/null
+++ b/package/rpcbind/0005-rpcbproc_callit_com-Stop-freeing-a-static-pointer.patch
@@ -0,0 +1,98 @@
+From 4e201b75928ff7d4894cd30ab0f5f67b9cd95f5c Mon Sep 17 00:00:00 2001
+From: Steve Dickson <steved@redhat.com>
+Date: Thu, 18 Jan 2018 17:33:56 +0000
+Subject: [PATCH] rpcbproc_callit_com: Stop freeing a static pointer
+
+commit 7ea36ee introduced a svc_freeargs() call
+that ended up freeing static pointer.
+
+It turns out the allocations for the rmt_args
+is not necessary . The xdr routines (xdr_bytes) will
+handle the memory management and the largest
+possible message size is UDPMSGSIZE (due to UDP only)
+which is smaller than RPC_BUF_MAX
+
+Signed-off-by: Steve Dickson <steved@redhat.com>
+(cherry picked from commit 7c7590ad536c0e24bef790cb1e65702fc54db566)
+Signed-off-by: Ed Blake <ed.blake@sondrel.com>
+---
+ src/rpcb_svc_com.c | 39 ++++++---------------------------------
+ 1 file changed, 6 insertions(+), 33 deletions(-)
+
+diff --git a/src/rpcb_svc_com.c b/src/rpcb_svc_com.c
+index 0432b6f..64f1104 100644
+--- a/src/rpcb_svc_com.c
++++ b/src/rpcb_svc_com.c
+@@ -616,9 +616,9 @@ rpcbproc_callit_com(struct svc_req *rqstp, SVCXPRT *transp,
+       struct netconfig *nconf;
+       struct netbuf *caller;
+       struct r_rmtcall_args a;
+-      char *buf_alloc = NULL, *outbufp;
++      char *outbufp;
+       char *outbuf_alloc = NULL;
+-      char buf[RPC_BUF_MAX], outbuf[RPC_BUF_MAX];
++      char  outbuf[RPC_BUF_MAX];
+       struct netbuf *na = (struct netbuf *) NULL;
+       struct rpc_msg call_msg;
+       int outlen;
+@@ -639,36 +639,10 @@ rpcbproc_callit_com(struct svc_req *rqstp, SVCXPRT *transp,
+       }
+       if (si.si_socktype != SOCK_DGRAM)
+               return; /* Only datagram type accepted */
+-      sendsz = __rpc_get_t_size(si.si_af, si.si_proto, UDPMSGSIZE);
+-      if (sendsz == 0) {      /* data transfer not supported */
+-              if (reply_type == RPCBPROC_INDIRECT)
+-                      svcerr_systemerr(transp);
+-              return;
+-      }
+-      /*
+-       * Should be multiple of 4 for XDR.
+-       */
+-      sendsz = ((sendsz + 3) / 4) * 4;
+-      if (sendsz > RPC_BUF_MAX) {
+-#ifdef        notyet
+-              buf_alloc = alloca(sendsz);             /* not in IDR2? */
+-#else
+-              buf_alloc = malloc(sendsz);
+-#endif        /* notyet */
+-              if (buf_alloc == NULL) {
+-                      if (debugging)
+-                              xlog(LOG_DEBUG,
+-                                      "rpcbproc_callit_com:  No Memory!\n");
+-                      if (reply_type == RPCBPROC_INDIRECT)
+-                              svcerr_systemerr(transp);
+-                      return;
+-              }
+-              a.rmt_args.args = buf_alloc;
+-      } else {
+-              a.rmt_args.args = buf;
+-      }
++      sendsz = UDPMSGSIZE;
+ 
+       call_msg.rm_xid = 0;    /* For error checking purposes */
++      memset(&a, 0, sizeof(a)); /* Zero out the input buffer */
+       if (!svc_getargs(transp, (xdrproc_t) xdr_rmtcall_args, (char *) &a)) {
+               if (reply_type == RPCBPROC_INDIRECT)
+                       svcerr_decode(transp);
+@@ -708,7 +682,8 @@ rpcbproc_callit_com(struct svc_req *rqstp, SVCXPRT *transp,
+       if (rbl == (rpcblist_ptr)NULL) {
+ #ifdef RPCBIND_DEBUG
+               if (debugging)
+-                      xlog(LOG_DEBUG, "not found\n");
++                      xlog(LOG_DEBUG, "prog %lu vers %lu: not found\n", 
++                              a.rmt_prog, a.rmt_vers);
+ #endif
+               if (reply_type == RPCBPROC_INDIRECT)
+                       svcerr_noprog(transp);
+@@ -941,8 +916,6 @@ out:
+       }
+       if (local_uaddr)
+               free(local_uaddr);
+-      if (buf_alloc)
+-              free(buf_alloc);
+       if (outbuf_alloc)
+               free(outbuf_alloc);
+       if (na) {
+-- 
+2.11.0
+

diff --git a/package/rpcbind/0006-pmapproc_dump-Fixed-typo-in-memory-leak-patch.patch b/package/rpcbind/0006-pmapproc_dump-Fixed-typo-in-memory-leak-patch.patch
new file mode 100644 (file)
index 0000000..11ce6a8
--- /dev/null
+++ b/package/rpcbind/0006-pmapproc_dump-Fixed-typo-in-memory-leak-patch.patch
@@ -0,0 +1,31 @@
+From d3f1f55e50e3c436a2ea91d60da84c3a94e6c53f Mon Sep 17 00:00:00 2001
+From: Steve Dickson <steved@redhat.com>
+Date: Thu, 18 Jan 2018 17:41:49 +0000
+Subject: [PATCH] pmapproc_dump: Fixed typo in memory leak patch
+
+commit 7ea36eee introduce a typo that caused
+NIS (aka ypbind) to fail.
+
+Signed-off-by: Steve Dickson <steved@redhat.com>
+(cherry picked from commit c49a7ea639eb700823e174fd605bbbe183e229aa)
+Signed-off-by: Ed Blake <ed.blake@sondrel.com>
+---
+ src/pmap_svc.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/pmap_svc.c b/src/pmap_svc.c
+index bb57b05..ffca7df 100644
+--- a/src/pmap_svc.c
++++ b/src/pmap_svc.c
+@@ -384,7 +384,7 @@ pmapproc_dump(struct svc_req *rqstp /*__unused*/, SVCXPRT *xprt)
+       }
+ 
+ done:
+-      if (!svc_freeargs(xprt, (xdrproc_t) xdr_pmap, (char *)NULL)) {
++      if (!svc_freeargs(xprt, (xdrproc_t) xdr_void, (char *)NULL)) {
+               if (debugging) {
+                       (void) xlog(LOG_DEBUG, "unable to free arguments\n");
+                       if (doabort) {
+-- 
+2.11.0
+