CVE-2026-98322: netfilter: nft_nat: fully initialise new_addr in netmap setup

CVE-2026-98322: netfilter: nft_nat: fully initialise new_addr in netmap setup

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

netfilter: nft_nat: fully initialise new_addr in netmap setup

nft_nat_setup_netmap() builds the mapped address in an on-stack
union nf_inet_addr. For an IPv4 mapping it writes only the 4-byte .ip
member and the loop runs a single 32-bit iteration, but it then copies
the whole 16-byte union into range->min_addr and range->max_addr, so the
upper 12 bytes reach nf_nat_setup_info() uninitialised.

KMSAN reports an uninit-value in nf_nat_setup_info() reached from
nft_nat_eval(). The IPv6 path fills all 16 bytes and is not affected.

Zero-initialise new_addr.

The Linux kernel CVE team has assigned CVE-2026-98322 to this issue.


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

	Issue introduced in 5.8 with commit 3ff7ddb1353da9b535e65702704cbadea1da9a00 and fixed in 5.10.271 with commit 29365695842db0a97b701a43a09fad1b4f7ecf3e
	Issue introduced in 5.8 with commit 3ff7ddb1353da9b535e65702704cbadea1da9a00 and fixed in 5.15.222 with commit 7b9380c38c2fd2189416fa602bdbc5c8523b84b2
	Issue introduced in 5.8 with commit 3ff7ddb1353da9b535e65702704cbadea1da9a00 and fixed in 6.1.189 with commit eb2030137dba3b59cbb5057a33af70488d6bc231
	Issue introduced in 5.8 with commit 3ff7ddb1353da9b535e65702704cbadea1da9a00 and fixed in 6.6.158 with commit e4982c489ee359162eee3ece1fb36082648464a5
	Issue introduced in 5.8 with commit 3ff7ddb1353da9b535e65702704cbadea1da9a00 and fixed in 6.12.112 with commit 161f5860c92a8ec80b6bdff16e79d70dcd8afc5a
	Issue introduced in 5.8 with commit 3ff7ddb1353da9b535e65702704cbadea1da9a00 and fixed in 6.18.54 with commit 0ce42c7b84032335abff9eac43762e4ca8224451
	Issue introduced in 5.8 with commit 3ff7ddb1353da9b535e65702704cbadea1da9a00 and fixed in 7.2.8 with commit 1c43f5db482f74b41987c39c9c375a5e767556eb
	Issue introduced in 5.8 with commit 3ff7ddb1353da9b535e65702704cbadea1da9a00 and fixed in 7.3-rc4 with commit d313499df66159b4b7971d760d16729598ab7e5a

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-2026-98322
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/nft_nat.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/29365695842db0a97b701a43a09fad1b4f7ecf3e
	https://git.kernel.org/stable/c/7b9380c38c2fd2189416fa602bdbc5c8523b84b2
	https://git.kernel.org/stable/c/eb2030137dba3b59cbb5057a33af70488d6bc231
	https://git.kernel.org/stable/c/e4982c489ee359162eee3ece1fb36082648464a5
	https://git.kernel.org/stable/c/161f5860c92a8ec80b6bdff16e79d70dcd8afc5a
	https://git.kernel.org/stable/c/0ce42c7b84032335abff9eac43762e4ca8224451
	https://git.kernel.org/stable/c/1c43f5db482f74b41987c39c9c375a5e767556eb
	https://git.kernel.org/stable/c/d313499df66159b4b7971d760d16729598ab7e5a