a6527128fe
[ Upstream commit b4ee93380b3c891fea996af8d1d3ca0e36ad31f0 ]
Looks like "tc" hard-codes "mangle" as the only supported table
name, but on kernel side there are no checks.
This is wrong. Not all xtables targets are safe to call from tc.
E.g. "nat" targets assume skb has a conntrack object assigned to it.
Normally those get called from netfilter nat core which consults the
nat table to obtain the address mapping.
"tc" userspace either sets PRE or POSTROUTING as hook number, but there
is no validation of this on kernel side, so update netlink policy to
reject bogus numbers. Some targets may assume skb_dst is set for
input/forward hooks, so prevent those from being used.
act_ipt uses the hook number in two places:
1. the state hook number, this is fine as-is
2. to set par.hook_mask
The latter is a bit mask, so update the assignment to make
xt_check_target() to the right thing.
Followup patch adds required checks for the skb/packet headers before
calling the targets evaluation function.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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.