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Eric Dumazet 9cb726a212 ip_tunnel: better validate user provided tunnel names
Use dev_valid_name() to make sure user does not provide illegal
device name.

syzbot caught the following bug :

BUG: KASAN: stack-out-of-bounds in strlcpy include/linux/string.h:300 [inline]
BUG: KASAN: stack-out-of-bounds in __ip_tunnel_create+0xca/0x6b0 net/ipv4/ip_tunnel.c:257
Write of size 20 at addr ffff8801ac79f810 by task syzkaller268107/4482

CPU: 0 PID: 4482 Comm: syzkaller268107 Not tainted 4.16.0+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b9/0x29f lib/dump_stack.c:53
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0xac/0x2f5 mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 memcpy+0x37/0x50 mm/kasan/kasan.c:303
 strlcpy include/linux/string.h:300 [inline]
 __ip_tunnel_create+0xca/0x6b0 net/ipv4/ip_tunnel.c:257
 ip_tunnel_create net/ipv4/ip_tunnel.c:352 [inline]
 ip_tunnel_ioctl+0x818/0xd40 net/ipv4/ip_tunnel.c:861
 ipip_tunnel_ioctl+0x1c5/0x420 net/ipv4/ipip.c:350
 dev_ifsioc+0x43e/0xb90 net/core/dev_ioctl.c:334
 dev_ioctl+0x69a/0xcc0 net/core/dev_ioctl.c:525
 sock_ioctl+0x47e/0x680 net/socket.c:1015
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1cf/0x1650 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 SYSC_ioctl fs/ioctl.c:708 [inline]
 SyS_ioctl+0x24/0x30 fs/ioctl.c:706
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Fixes: c544193214 ("GRE: Refactor GRE tunneling code.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-05 15:16:15 -04:00
arch Char/Misc patches for 4.17-rc1 2018-04-04 20:07:20 -07:00
block Char/Misc patches for 4.17-rc1 2018-04-04 20:07:20 -07:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-04-04 17:11:08 -07:00
Documentation Char/Misc patches for 4.17-rc1 2018-04-04 20:07:20 -07:00
drivers Char/Misc patches for 4.17-rc1 2018-04-04 20:07:20 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Char/Misc patches for 4.17-rc1 2018-04-04 20:07:20 -07:00
include Char/Misc patches for 4.17-rc1 2018-04-04 20:07:20 -07:00
init Merge branch 'syscalls-next' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux 2018-04-02 21:22:12 -07:00
ipc Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-04-03 19:15:32 -07:00
kernel Driver core patches for 4.17-rc1 2018-04-04 19:41:45 -07:00
lib Char/Misc patches for 4.17-rc1 2018-04-04 20:07:20 -07:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
mm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next 2018-04-03 14:08:58 -07:00
net ip_tunnel: better validate user provided tunnel names 2018-04-05 15:16:15 -04:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-04-03 14:04:18 -07:00
scripts RISC-V changes for 4.17 2018-04-04 16:43:47 -07:00
security Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-04-03 19:15:32 -07:00
sound Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-04-03 14:04:18 -07:00
tools Char/Misc patches for 4.17-rc1 2018-04-04 20:07:20 -07:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt kvm/arm fixes for 4.16, take 2 2018-03-15 21:45:37 +01:00
.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 kbuild: move include/config/ksym/* to include/ksym/* 2018-03-26 02:01:23 +09:00
.mailmap Merge remote-tracking branch 'spi/topic/samsung' into spi-next 2018-04-02 15:56:32 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Char/Misc patches for 4.17-rc1 2018-04-04 20:07:20 -07:00
Makefile Kconfig updates for v4.17 2018-04-03 16:28:01 -07:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

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

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

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.