Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:50538 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753901AbeCGOJF (ORCPT ); Wed, 7 Mar 2018 09:09:05 -0500 From: Steve Dickson To: Libtirpc-devel Mailing List Cc: Linux NFS Mailing list Subject: [PATCH V2] clnt_dg_call: Change the memory allocation Date: Wed, 7 Mar 2018 09:09:03 -0500 Message-Id: <20180307140903.13278-1-steved@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Commit 2936f109590e add free()s on memory that was allocated from the stack (via alloca()). That type memory is automatically freed so those added free()s was causing a double frees. It was suggested allocating memory from the stack can be a bit troublesome. So this patch changes the memory allocation from the stack to the heap which also eliminates the double frees. Fixes: 2936f109590e ("clnt_dg_call: Fix a buffer overflow (CVE-2016-4429)") BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1552163 Signed-off-by: Steve Dickson --- src/clnt_dg.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/clnt_dg.c b/src/clnt_dg.c index 884a2db..04a2aba 100644 --- a/src/clnt_dg.c +++ b/src/clnt_dg.c @@ -430,7 +430,7 @@ get_reply: struct sockaddr_in err_addr; struct sockaddr_in *sin = (struct sockaddr_in *)&cu->cu_raddr; struct iovec iov; - char *cbuf = (char *) alloca (outlen + 256); + char *cbuf = (char *) mem_alloc((outlen + 256)); int ret; if (cbuf == NULL) @@ -462,13 +462,13 @@ get_reply: cmsg = CMSG_NXTHDR (&msg, cmsg)) if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR) { - free(cbuf); + mem_free(cbuf, (outlen + 256)); e = (struct sock_extended_err *) CMSG_DATA(cmsg); cu->cu_error.re_errno = e->ee_errno; release_fd_lock(cu->cu_fd, mask); return (cu->cu_error.re_status = RPC_CANTRECV); } - free(cbuf); + mem_free(cbuf, (outlen + 256)); } #endif -- 2.14.3