Pablo Neira Ayuso 2d15663304 netfilter: conntrack: refetch conntrack after nf_conntrack_update()
[ Upstream commit d005fbb855d3b5660d62ee5a6bd2d99c13ff8cf3 ]

__nf_conntrack_update() might refresh the conntrack object that is
attached to the skbuff. Otherwise, this triggers UAF.

[  633.200434] ==================================================================
[  633.200472] BUG: KASAN: use-after-free in nf_conntrack_update+0x34e/0x770 [nf_conntrack]
[  633.200478] Read of size 1 at addr ffff888370804c00 by task nfqnl_test/6769

[  633.200487] CPU: 1 PID: 6769 Comm: nfqnl_test Not tainted 5.8.0-rc2+ #388
[  633.200490] Hardware name: LENOVO 23259H1/23259H1, BIOS G2ET32WW (1.12 ) 05/30/2012
[  633.200491] Call Trace:
[  633.200499]  dump_stack+0x7c/0xb0
[  633.200526]  ? nf_conntrack_update+0x34e/0x770 [nf_conntrack]
[  633.200532]  print_address_description.constprop.6+0x1a/0x200
[  633.200539]  ? _raw_write_lock_irqsave+0xc0/0xc0
[  633.200568]  ? nf_conntrack_update+0x34e/0x770 [nf_conntrack]
[  633.200594]  ? nf_conntrack_update+0x34e/0x770 [nf_conntrack]
[  633.200598]  kasan_report.cold.9+0x1f/0x42
[  633.200604]  ? call_rcu+0x2c0/0x390
[  633.200633]  ? nf_conntrack_update+0x34e/0x770 [nf_conntrack]
[  633.200659]  nf_conntrack_update+0x34e/0x770 [nf_conntrack]
[  633.200687]  ? nf_conntrack_find_get+0x30/0x30 [nf_conntrack]

Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1436
Fixes: ee04805ff54a ("netfilter: conntrack: make conntrack userspace helpers work again")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-16 08:16:38 +02:00
2020-06-24 17:50:48 +02:00
2019-09-22 10:34:46 -07:00
2019-11-10 13:41:59 -08:00
2020-07-09 09:37:57 +02:00

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.
Description
No description provided
Readme 5.7 GiB
Languages
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%