glibc/sysdeps/unix/sysv/linux/netlinkaccess.h
Florian Weimer 2eecc8afd0 Terminate process on invalid netlink response from kernel [BZ #12926]
The recvmsg system calls for netlink sockets have been particularly
prone to picking up unrelated data after a file descriptor race
(where the descriptor is closed and reopened concurrently in a
multi-threaded process, as the result of a file descriptor
management issue elsewhere).  This commit adds additional error
checking and aborts the process if a datagram of unexpected length
(without the netlink header) is received, or an error code which
cannot happen due to the way the netlink socket is used.

	[BZ #12926]
	Terminate process on invalid netlink response.
	* sysdeps/unix/sysv/linux/netlinkaccess.h
	(__netlink_assert_response): Declare.
	* sysdeps/unix/sysv/linux/netlink_assert_response.c: New file.
	* sysdeps/unix/sysv/linux/Makefile [$(subdir) == inet]
	(sysdep_routines): Add netlink_assert_response.
	* sysdeps/unix/sysv/linux/check_native.c (__check_native): Call
	__netlink_assert_response.
	* sysdeps/unix/sysv/linux/check_pf.c (make_request): Likewise.
	* sysdeps/unix/sysv/linux/ifaddrs.c (__netlink_request): Likewise.
	* sysdeps/unix/sysv/linux/Versions (GLIBC_PRIVATE): Add
	__netlink_assert_response.
2015-11-09 12:48:41 +01:00

59 lines
1.9 KiB
C

/* Copyright (C) 2004-2015 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
<http://www.gnu.org/licenses/>. */
#ifndef _NETLINKACCESS_H
#define _NETLINKACCESS_H 1
#include <stdint.h>
#include <sys/types.h>
#include <asm/types.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
struct netlink_res
{
struct netlink_res *next;
struct nlmsghdr *nlh;
size_t size; /* Size of response. */
uint32_t seq; /* sequential number we used. */
};
struct netlink_handle
{
int fd; /* Netlink file descriptor. */
pid_t pid; /* Process ID. */
uint32_t seq; /* The sequence number we use currently. */
struct netlink_res *nlm_list; /* Pointer to list of responses. */
struct netlink_res *end_ptr; /* For faster append of new entries. */
};
extern int __netlink_open (struct netlink_handle *h);
extern void __netlink_close (struct netlink_handle *h);
extern void __netlink_free_handle (struct netlink_handle *h);
extern int __netlink_request (struct netlink_handle *h, int type);
/* Terminate the process if RESULT is an invalid recvmsg result for
the netlink socket FD. */
void __netlink_assert_response (int fd, ssize_t result)
internal_function;
libc_hidden_proto (__netlink_assert_response)
#endif /* netlinkaccess.h */