CVE-2022-23219: Buffer overflow in sunrpc clnt_create for "unix" (bug 22542)

Processing an overlong pathname in the sunrpc clnt_create function
results in a stack-based buffer overflow.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit 226b46770c82899b555986583294b049c6ec9b40)

diff --git a/NEWS b/NEWS
index 4d52ccfaa0cee4dd23246417e4c83a1f23da20e4..ba7b0cc51111730dcd2ee3eeb0ad3cc025bd4a93 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,7 @@ The following bugs are resolved with this release:
     (CVE-2016-10228)
   [20019] NULL pointer dereference in libc.so.6 IFUNC due to uninitialized GOT
   [20543] Please move from .gnu.linkonce to comdat
+  [22542] CVE-2022-23219: Buffer overflow in sunrpc clnt_create for "unix"
   [23296] Data race in setting function descriptor during lazy binding
   [24973] iconv encounters segmentation fault when converting 0x00 0xfe in
     EUC-KR to UTF-8 (CVE-2019-25013)
@@ -67,6 +68,10 @@ Security related changes:
 
   CVE-2020-29562: An assertion failure has been fixed in the iconv function
   when invoked with UCS4 input containing an invalid character.
+
+  CVE-2022-23219: Passing an overlong file name to the clnt_create
+  legacy function could result in a stack-based buffer overflow when
+  using the "unix" protocol.  Reported by Martin Sebor.
 \f
 Version 2.31
 

diff --git a/sunrpc/clnt_gen.c b/sunrpc/clnt_gen.c
index 13ced8994e49d4ee744a35c3ac4bd840f5d0abb5..b44357cd88e60599b82635618229109fe91855a0 100644 (file)
--- a/sunrpc/clnt_gen.c
+++ b/sunrpc/clnt_gen.c
@@ -57,9 +57,13 @@ clnt_create (const char *hostname, u_long prog, u_long vers,
 
   if (strcmp (proto, "unix") == 0)
     {
-      memset ((char *)&sun, 0, sizeof (sun));
-      sun.sun_family = AF_UNIX;
-      strcpy (sun.sun_path, hostname);
+      if (__sockaddr_un_set (&sun, hostname) < 0)
+       {
+         struct rpc_createerr *ce = &get_rpc_createerr ();
+         ce->cf_stat = RPC_SYSTEMERROR;
+         ce->cf_error.re_errno = errno;
+         return NULL;
+       }
       sock = RPC_ANYSOCK;
       client = clntunix_create (&sun, prog, vers, &sock, 0, 0);
       if (client == NULL)