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Filename Latest commit message Latest commit date
WANG Cong c800aaf8d8 packet: fix use-after-free in prb_retire_rx_blk_timer_expired()
There are multiple reports showing we have a use-after-free in
the timer prb_retire_rx_blk_timer_expired(), where we use struct
tpacket_kbdq_core::pkbdq, a pg_vec, after it gets freed by
free_pg_vec().

The interesting part is it is not freed via packet_release() but
via packet_setsockopt(), which means we are not closing the socket.
Looking into the big and fat function packet_set_ring(), this could
happen if we satisfy the following conditions:

1. closing == 0, not on packet_release() path
2. req->tp_block_nr == 0, we don't allocate a new pg_vec
3. rx_ring->pg_vec is already set as V3, which means we already called
   packet_set_ring() wtih req->tp_block_nr > 0 previously
4. req->tp_frame_nr == 0, pass sanity check
5. po->mapped == 0, never called mmap()

In this scenario we are clearing the old rx_ring->pg_vec, so we need
to free this pg_vec, but we don't stop the timer on this path because
of closing==0.

The timer has to be stopped as long as we need to free pg_vec, therefore
the check on closing!=0 is wrong, we should check pg_vec!=NULL instead.

Thanks to liujian for testing different fixes.

Reported-by: alexander.levin@verizon.com
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Reported-by: liujian (CE) <liujian56@huawei.com>
Tested-by: liujian (CE) <liujian56@huawei.com>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-24 17:33:19 -07:00
arch x86: mark kprobe templates as character arrays, not single characters 2017-07-20 11:34:47 -07:00
block
certs modsign: add markers to endif-statements in certs/Makefile 2017-07-14 11:01:37 +10:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-07-14 22:49:50 -07:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-07-20 16:33:39 -07:00
drivers ftgmac100: Make the MDIO bus a child of the ethernet device 2017-07-24 17:23:55 -07:00
firmware
fs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2017-07-20 10:41:12 -07:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-07-20 16:33:39 -07:00
init
ipc
kernel bpf/verifier: fix min/max handling in BPF_SUB 2017-07-24 14:02:55 -07:00
lib lib: test_rhashtable: fix for large entry counts 2017-07-24 14:13:58 -07:00
mm Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
net packet: fix use-after-free in prb_retire_rx_blk_timer_expired() 2017-07-24 17:33:19 -07:00
samples
scripts
security Now that IPC and other changes have landed, enable manual markings for 2017-07-19 08:55:18 -07:00
sound sound fixes for 4.13-rc1 2017-07-14 12:44:00 -07:00
tools selftests/bpf: subtraction bounds test 2017-07-24 14:02:55 -07:00
usr
virt Second batch of KVM updates for v4.13 2017-07-15 10:18:16 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS libnvdimm for 4.13-rc2 2017-07-20 10:17:53 -07:00
Makefile Linux v4.13-rc1 2017-07-15 15:22:10 -07:00
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.