CVE-2024-26609: netfilter: nf_tables: reject QUEUE/DROP verdict parameters

[Lee Jones <lee@kernel.org>]

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_tables: reject QUEUE/DROP verdict parameters

This reverts commit e0abdadcc6e1.

core.c:nf_hook_slow assumes that the upper 16 bits of NF_DROP
verdicts contain a valid errno, i.e. -EPERM, -EHOSTUNREACH or similar,
or 0.

Due to the reverted commit, its possible to provide a positive
value, e.g. NF_ACCEPT (1), which results in use-after-free.

Its not clear to me why this commit was made.

NF_QUEUE is not used by nftables; "queue" rules in nftables
will result in use of "nft_queue" expression.

If we later need to allow specifiying errno values from userspace
(do not know why), this has to call NF_DROP_GETERR and check that
"err <= 0" holds true.

The Linux kernel CVE team has assigned CVE-2024-26609 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 3.15 with commit e0abdadcc6e1 and fixed in 4.19.307 with commit 8365e9d92b85
	Issue introduced in 3.15 with commit e0abdadcc6e1 and fixed in 5.4.269 with commit 4e66422f1b56
	Issue introduced in 3.15 with commit e0abdadcc6e1 and fixed in 5.10.210 with commit 55a60251fa50
	Issue introduced in 3.15 with commit e0abdadcc6e1 and fixed in 5.15.149 with commit 960cf4f81253
	Issue introduced in 3.15 with commit e0abdadcc6e1 and fixed in 6.1.76 with commit 8e34430e33b8
	Issue introduced in 3.15 with commit e0abdadcc6e1 and fixed in 6.6.15 with commit 6653118b176a
	Issue introduced in 3.15 with commit e0abdadcc6e1 and fixed in 6.7.3 with commit f05a497e7bc8
	Issue introduced in 3.15 with commit e0abdadcc6e1 and fixed in 6.8-rc2 with commit f342de4e2f33

Please see https://www.kernel.org or a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-26609
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	net/netfilter/nf_tables_api.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/8365e9d92b85fda975a5ece7a3a139cb964018c8
	https://git.kernel.org/stable/c/4e66422f1b56149761dc76030e6345d1cca6f869
	https://git.kernel.org/stable/c/55a60251fa50d4e68175e36666b536a602ce4f6c
	https://git.kernel.org/stable/c/960cf4f812530f01f6acc6878ceaa5404c06af7b
	https://git.kernel.org/stable/c/8e34430e33b8a80bc014f3efe29cac76bc30a4b4
	https://git.kernel.org/stable/c/6653118b176a00915125521c6572ae8e507621db
	https://git.kernel.org/stable/c/f05a497e7bc8851eeeb3a58da180ba469efebb05
	https://git.kernel.org/stable/c/f342de4e2f33e0e39165d8639387aa6c19dff660