Subject: CVE-2024-35898: netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get()

From: Greg Kroah-Hartman <[email-masked]>

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

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

netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get()

nft_unregister_flowtable_type() within nf_flow_inet_module_exit() can
concurrent with __nft_flowtable_type_get() within nf_tables_newflowtable().
And thhere is not any protection when iterate over nf_tables_flowtables
list in __nft_flowtable_type_get(). Therefore, there is pertential
data-race of nf_tables_flowtables list entry.

Use list_for_each_entry_rcu() to iterate over nf_tables_flowtables list
in __nft_flowtable_type_get(), and use rcu_read_lock() in the caller
nft_flowtable_type_get() to protect the entire type query process.

The Linux kernel CVE team has assigned CVE-2024-35898 to this issue.

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

	Issue introduced in 4.16 with commit 3b49e2e94e6e and fixed in 4.19.312 with commit 69d1fe14a680
	Issue introduced in 4.16 with commit 3b49e2e94e6e and fixed in 5.4.274 with commit a347bc8e6251
	Issue introduced in 4.16 with commit 3b49e2e94e6e and fixed in 5.10.215 with commit 940d41caa71f
	Issue introduced in 4.16 with commit 3b49e2e94e6e and fixed in 5.15.154 with commit 2485bcfe05ee
	Issue introduced in 4.16 with commit 3b49e2e94e6e and fixed in 6.1.85 with commit 9b5b7708ec2b
	Issue introduced in 4.16 with commit 3b49e2e94e6e and fixed in 6.6.26 with commit 8b891153b2e4
	Issue introduced in 4.16 with commit 3b49e2e94e6e and fixed in 6.8.5 with commit e684b1674fd1
	Issue introduced in 4.16 with commit 3b49e2e94e6e and fixed in 6.9 with commit 24225011d81b

Please see https://www.kernel.org for 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-2024-35898
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/69d1fe14a680042ec913f22196b58e2c8ff1b007
	https://git.kernel.org/stable/c/a347bc8e6251eaee4b619da28020641eb5b0dd77
	https://git.kernel.org/stable/c/940d41caa71f0d3a52df2fde5fada524a993e331
	https://git.kernel.org/stable/c/2485bcfe05ee3cf9ca8923a94fa2e456924c79c8
	https://git.kernel.org/stable/c/9b5b7708ec2be21dd7ef8ca0e3abe4ae9f3b083b
	https://git.kernel.org/stable/c/8b891153b2e4dc0ca9d9dab8f619d49c740813df
	https://git.kernel.org/stable/c/e684b1674fd1ca4361812a491242ae871d6b2859
	https://git.kernel.org/stable/c/24225011d81b471acc0e1e315b7d9905459a6304