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Dave Jones a98f917589 ipv6: handle -EFAULT from skb_copy_bits
By setting certain socket options on ipv6 raw sockets, we can confuse the
length calculation in rawv6_push_pending_frames triggering a BUG_ON.

RIP: 0010:[<ffffffff817c6390>] [<ffffffff817c6390>] rawv6_sendmsg+0xc30/0xc40
RSP: 0018:ffff881f6c4a7c18  EFLAGS: 00010282
RAX: 00000000fffffff2 RBX: ffff881f6c681680 RCX: 0000000000000002
RDX: ffff881f6c4a7cf8 RSI: 0000000000000030 RDI: ffff881fed0f6a00
RBP: ffff881f6c4a7da8 R08: 0000000000000000 R09: 0000000000000009
R10: ffff881fed0f6a00 R11: 0000000000000009 R12: 0000000000000030
R13: ffff881fed0f6a00 R14: ffff881fee39ba00 R15: ffff881fefa93a80

Call Trace:
 [<ffffffff8118ba23>] ? unmap_page_range+0x693/0x830
 [<ffffffff81772697>] inet_sendmsg+0x67/0xa0
 [<ffffffff816d93f8>] sock_sendmsg+0x38/0x50
 [<ffffffff816d982f>] SYSC_sendto+0xef/0x170
 [<ffffffff816da27e>] SyS_sendto+0xe/0x10
 [<ffffffff81002910>] do_syscall_64+0x50/0xa0
 [<ffffffff817f7cbc>] entry_SYSCALL64_slow_path+0x25/0x25

Handle by jumping to the failure path if skb_copy_bits gets an EFAULT.

Reproducer:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define LEN 504

int main(int argc, char* argv[])
{
	int fd;
	int zero = 0;
	char buf[LEN];

	memset(buf, 0, LEN);

	fd = socket(AF_INET6, SOCK_RAW, 7);

	setsockopt(fd, SOL_IPV6, IPV6_CHECKSUM, &zero, 4);
	setsockopt(fd, SOL_IPV6, IPV6_DSTOPTS, &buf, LEN);

	sendto(fd, buf, 1, 0, (struct sockaddr *) buf, 110);
}

Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-23 12:20:39 -05:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-20 15:48:34 -08:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-20 15:48:34 -08:00
block Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2016-12-14 17:21:53 -08:00
certs certs: Add a secondary system keyring that can be added to dynamically 2016-04-11 22:48:09 +01:00
crypto This pull contains one set of changes: a conversion of the crypto DocBook 2016-12-17 16:00:34 -08:00
drivers stmmac: CSR clock configuration fix 2016-12-23 11:46:37 -05:00
firmware WHENCE: use https://linuxtv.org for LinuxTV URLs 2015-12-04 10:35:11 -02:00
fs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2016-12-19 08:23:53 -08:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-20 15:48:34 -08:00
init Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-17 20:17:04 -08:00
ipc ipc/sem: avoid idr tree lookup for interrupted semop 2016-12-14 16:04:08 -08:00
kernel kcov: make kcov work properly with KASLR enabled 2016-12-20 09:48:47 -08:00
lib printk: fix typo in CONSOLE_LOGLEVEL_DEFAULT help text 2016-12-20 09:48:47 -08:00
mm mm: fadvise: avoid expensive remote LRU cache draining after FADV_DONTNEED 2016-12-20 09:48:46 -08:00
net ipv6: handle -EFAULT from skb_copy_bits 2016-12-23 12:20:39 -05:00
samples Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-12-17 16:24:13 -08:00
scripts Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-12-17 16:32:27 -08:00
security ima: platform-independent hash value 2016-12-20 09:48:46 -08:00
sound sound updates for 4.10-rc1 2016-12-14 11:14:28 -08:00
tools libnvdimm for 4.10 2016-12-18 15:49:10 -08:00
usr initramfs: allow again choice of the embedded initram compression algorithm 2016-12-14 16:04:08 -08:00
virt mm: unexport __get_user_pages_unlocked() 2016-12-14 16:04:09 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-08-02 16:48:52 -04:00
.mailmap Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-10-15 09:26:12 -07:00
COPYING
CREDITS Merge branch 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-12 15:23:02 -08:00
Kbuild scripts/gdb: provide linux constants 2016-05-23 17:04:14 -07:00
Kconfig
MAINTAINERS platform-drivers-x86 for 4.10-2 2016-12-18 15:45:33 -08:00
Makefile Linux 4.9 2016-12-11 11:17:54 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.