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Davide Caratti a7a12b5a0f net/sched: act_tunnel_key: fix OOB write in case of IPv6 ERSPAN tunnels
the following command

 # tc action add action tunnel_key \
 > set src_ip 2001:db8::1 dst_ip 2001:db8::2 id 10 erspan_opts 1:6789:0:0

generates the following splat:

 BUG: KASAN: slab-out-of-bounds in tunnel_key_copy_opts+0xcc9/0x1010 [act_tunnel_key]
 Write of size 4 at addr ffff88813f5f1cc8 by task tc/873

 CPU: 2 PID: 873 Comm: tc Not tainted 5.9.0+ #282
 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014
 Call Trace:
  dump_stack+0x99/0xcb
  print_address_description.constprop.7+0x1e/0x230
  kasan_report.cold.13+0x37/0x7c
  tunnel_key_copy_opts+0xcc9/0x1010 [act_tunnel_key]
  tunnel_key_init+0x160c/0x1f40 [act_tunnel_key]
  tcf_action_init_1+0x5b5/0x850
  tcf_action_init+0x15d/0x370
  tcf_action_add+0xd9/0x2f0
  tc_ctl_action+0x29b/0x3a0
  rtnetlink_rcv_msg+0x341/0x8d0
  netlink_rcv_skb+0x120/0x380
  netlink_unicast+0x439/0x630
  netlink_sendmsg+0x719/0xbf0
  sock_sendmsg+0xe2/0x110
  ____sys_sendmsg+0x5ba/0x890
  ___sys_sendmsg+0xe9/0x160
  __sys_sendmsg+0xd3/0x170
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f872a96b338
 Code: 89 02 48 c7 c0 ff ff ff ff eb b5 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 8d 05 25 43 2c 00 8b 00 85 c0 75 17 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 41 54 41 89 d4 55
 RSP: 002b:00007ffffe367518 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
 RAX: ffffffffffffffda RBX: 000000005f8f5aed RCX: 00007f872a96b338
 RDX: 0000000000000000 RSI: 00007ffffe367580 RDI: 0000000000000003
 RBP: 0000000000000000 R08: 0000000000000001 R09: 000000000000001c
 R10: 000000000000000b R11: 0000000000000246 R12: 0000000000000001
 R13: 0000000000686760 R14: 0000000000000601 R15: 0000000000000000

 Allocated by task 873:
  kasan_save_stack+0x19/0x40
  __kasan_kmalloc.constprop.7+0xc1/0xd0
  __kmalloc+0x151/0x310
  metadata_dst_alloc+0x20/0x40
  tunnel_key_init+0xfff/0x1f40 [act_tunnel_key]
  tcf_action_init_1+0x5b5/0x850
  tcf_action_init+0x15d/0x370
  tcf_action_add+0xd9/0x2f0
  tc_ctl_action+0x29b/0x3a0
  rtnetlink_rcv_msg+0x341/0x8d0
  netlink_rcv_skb+0x120/0x380
  netlink_unicast+0x439/0x630
  netlink_sendmsg+0x719/0xbf0
  sock_sendmsg+0xe2/0x110
  ____sys_sendmsg+0x5ba/0x890
  ___sys_sendmsg+0xe9/0x160
  __sys_sendmsg+0xd3/0x170
  do_syscall_64+0x33/0x40
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

 The buggy address belongs to the object at ffff88813f5f1c00
  which belongs to the cache kmalloc-256 of size 256
 The buggy address is located 200 bytes inside of
  256-byte region [ffff88813f5f1c00, ffff88813f5f1d00)
 The buggy address belongs to the page:
 page:0000000011b48a19 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13f5f0
 head:0000000011b48a19 order:1 compound_mapcount:0
 flags: 0x17ffffc0010200(slab|head)
 raw: 0017ffffc0010200 0000000000000000 0000000d00000001 ffff888107c43400
 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
 page dumped because: kasan: bad access detected

 Memory state around the buggy address:
  ffff88813f5f1b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff88813f5f1c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 >ffff88813f5f1c80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
                                               ^
  ffff88813f5f1d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff88813f5f1d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

using IPv6 tunnels, act_tunnel_key allocates a fixed amount of memory for
the tunnel metadata, but then it expects additional bytes to store tunnel
specific metadata with tunnel_key_copy_opts().

Fix the arguments of __ipv6_tun_set_dst(), so that 'md_size' contains the
size previously computed by tunnel_key_get_opts_len(), like it's done for
IPv4 tunnels.

Fixes: 0ed5269f9e ("net/sched: add tunnel option support to act_tunnel_key")
Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Link: https://lore.kernel.org/r/36ebe969f6d13ff59912d6464a4356fe6f103766.1603231100.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-20 21:10:41 -07:00
arch networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
block - Improve DM core's bio splitting to use blk_max_size_offset(). Also 2020-10-14 15:05:38 -07:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto drivers-5.10-2020-10-12 2020-10-13 13:04:41 -07:00
Documentation netsec: ignore 'phy-mode' device property on ACPI systems 2020-10-20 15:59:43 -07:00
drivers net: dsa: bcm_sf2: make const array static, makes object smaller 2020-10-20 20:57:57 -07:00
fs networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
include networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
init networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
lib networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
net net/sched: act_tunnel_key: fix OOB write in case of IPv6 ERSPAN tunnels 2020-10-20 21:10:41 -07:00
samples networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
scripts networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
security networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
sound dma-mapping updates for 5.10 2020-10-15 14:43:29 -07:00
tools selftests: rtnetlink: load fou module for kci_test_encap_fou() test 2020-10-19 17:55:29 -07:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt KVM: fix memory leak in kvm_io_bus_unregister_dev() 2020-09-11 13:15:11 -04:00
.clang-format memblock: use separate iterators for memory and reserved regions 2020-10-13 18:38:35 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap As hoped, things calmed down for docs this cycle; fewer changes and almost 2020-10-12 16:21:29 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
Makefile networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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.

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.