Eric Dumazet b4cdf5066c net_sched: ematch: reject invalid TCF_EM_SIMPLE
[ Upstream commit 55cd9f67f1e45de8517cdaab985fb8e56c0bc1d8 ]

It is possible for malicious userspace to set TCF_EM_SIMPLE bit
even for matches that should not have this bit set.

This can fool two places using tcf_em_is_simple()

1) tcf_em_tree_destroy() -> memory leak of em->data
   if ops->destroy() is NULL

2) tcf_em_tree_dump() wrongly report/leak 4 low-order bytes
   of a kernel pointer.

BUG: memory leak
unreferenced object 0xffff888121850a40 (size 32):
  comm "syz-executor927", pid 7193, jiffies 4294941655 (age 19.840s)
  hex dump (first 32 bytes):
    00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000f67036ea>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
    [<00000000f67036ea>] slab_post_alloc_hook mm/slab.h:586 [inline]
    [<00000000f67036ea>] slab_alloc mm/slab.c:3320 [inline]
    [<00000000f67036ea>] __do_kmalloc mm/slab.c:3654 [inline]
    [<00000000f67036ea>] __kmalloc_track_caller+0x165/0x300 mm/slab.c:3671
    [<00000000fab0cc8e>] kmemdup+0x27/0x60 mm/util.c:127
    [<00000000d9992e0a>] kmemdup include/linux/string.h:453 [inline]
    [<00000000d9992e0a>] em_nbyte_change+0x5b/0x90 net/sched/em_nbyte.c:32
    [<000000007e04f711>] tcf_em_validate net/sched/ematch.c:241 [inline]
    [<000000007e04f711>] tcf_em_tree_validate net/sched/ematch.c:359 [inline]
    [<000000007e04f711>] tcf_em_tree_validate+0x332/0x46f net/sched/ematch.c:300
    [<000000007a769204>] basic_set_parms net/sched/cls_basic.c:157 [inline]
    [<000000007a769204>] basic_change+0x1d7/0x5f0 net/sched/cls_basic.c:219
    [<00000000e57a5997>] tc_new_tfilter+0x566/0xf70 net/sched/cls_api.c:2104
    [<0000000074b68559>] rtnetlink_rcv_msg+0x3b2/0x4b0 net/core/rtnetlink.c:5415
    [<00000000b7fe53fb>] netlink_rcv_skb+0x61/0x170 net/netlink/af_netlink.c:2477
    [<00000000e83a40d0>] rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5442
    [<00000000d62ba933>] netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
    [<00000000d62ba933>] netlink_unicast+0x223/0x310 net/netlink/af_netlink.c:1328
    [<0000000088070f72>] netlink_sendmsg+0x2c0/0x570 net/netlink/af_netlink.c:1917
    [<00000000f70b15ea>] sock_sendmsg_nosec net/socket.c:639 [inline]
    [<00000000f70b15ea>] sock_sendmsg+0x54/0x70 net/socket.c:659
    [<00000000ef95a9be>] ____sys_sendmsg+0x2d0/0x300 net/socket.c:2330
    [<00000000b650f1ab>] ___sys_sendmsg+0x8a/0xd0 net/socket.c:2384
    [<0000000055bfa74a>] __sys_sendmsg+0x80/0xf0 net/socket.c:2417
    [<000000002abac183>] __do_sys_sendmsg net/socket.c:2426 [inline]
    [<000000002abac183>] __se_sys_sendmsg net/socket.c:2424 [inline]
    [<000000002abac183>] __x64_sys_sendmsg+0x23/0x30 net/socket.c:2424

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+03c4738ed29d5d366ddf@syzkaller.appspotmail.com
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-05 14:18:09 +00:00
2020-01-27 14:46:19 +01:00
2020-01-29 15:02:39 +01:00

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.
Description
No description provided
Readme 1.4 GiB
Languages
C 98.1%
Assembly 1.2%
Makefile 0.3%