commit 6890b8a3ae40ab9d4c96024ab95b04816fcc8a4a Author: Florian Weimer Date: Mon Jan 17 11:49:25 2022 +0100 CVE-2022-23218: Buffer overflow in sunrpc svcunix_create (bug 28768) The sunrpc function svcunix_create suffers from a stack-based buffer overflow with overlong pathname arguments. Reviewed-by: Siddhesh Poyarekar (cherry picked from commit f545ad4928fa1f27a3075265182b38a4f939a5f7) diff --git a/sunrpc/Makefile b/sunrpc/Makefile index a4281b18d04c78e9..6408ab5c073538e9 100644 --- a/sunrpc/Makefile +++ b/sunrpc/Makefile @@ -65,7 +65,7 @@ shared-only-routines = $(routines) endif tests = tst-xdrmem tst-xdrmem2 test-rpcent tst-udp-error tst-udp-timeout \ - tst-udp-nonblocking tst-bug22542 + tst-udp-nonblocking tst-bug22542 tst-bug28768 xtests := tst-getmyaddr diff --git a/sunrpc/svc_unix.c b/sunrpc/svc_unix.c index 679fbe9cb69587bd..46f8d16fe94a3d4f 100644 --- a/sunrpc/svc_unix.c +++ b/sunrpc/svc_unix.c @@ -154,7 +154,10 @@ svcunix_create (int sock, u_int sendsize, u_int recvsize, char *path) SVCXPRT *xprt; struct unix_rendezvous *r; struct sockaddr_un addr; - socklen_t len = sizeof (struct sockaddr_in); + socklen_t len = sizeof (addr); + + if (__sockaddr_un_set (&addr, path) < 0) + return NULL; if (sock == RPC_ANYSOCK) { @@ -165,12 +168,6 @@ svcunix_create (int sock, u_int sendsize, u_int recvsize, char *path) } madesock = TRUE; } - memset (&addr, '\0', sizeof (addr)); - addr.sun_family = AF_UNIX; - len = strlen (path) + 1; - memcpy (addr.sun_path, path, len); - len += sizeof (addr.sun_family); - __bind (sock, (struct sockaddr *) &addr, len); if (__getsockname (sock, (struct sockaddr *) &addr, &len) != 0 diff --git a/sunrpc/tst-bug28768.c b/sunrpc/tst-bug28768.c new file mode 100644 index 0000000000000000..35a4b7b0b3d34350 --- /dev/null +++ b/sunrpc/tst-bug28768.c @@ -0,0 +1,42 @@ +/* Test to verify that long path is rejected by svcunix_create (bug 28768). + Copyright (C) 2022 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include + +/* svcunix_create does not have a default version in linkobj/libc.so. */ +compat_symbol_reference (libc, svcunix_create, svcunix_create, GLIBC_2_1); + +static int +do_test (void) +{ + char pathname[109]; + memset (pathname, 'x', sizeof (pathname)); + pathname[sizeof (pathname) - 1] = '\0'; + + errno = 0; + TEST_VERIFY (svcunix_create (RPC_ANYSOCK, 4096, 4096, pathname) == NULL); + TEST_COMPARE (errno, EINVAL); + + return 0; +} + +#include