CVE-2026-72223: nvdimm/btt: Free arena sub-allocations on discover_arenas() error path

CVE-2026-72223: nvdimm/btt: Free arena sub-allocations on discover_arenas() error path

[Greg Kroah-Hartman]

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

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

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

nvdimm/btt: Free arena sub-allocations on discover_arenas() error path

Memory allocated by btt_freelist_init(), btt_rtt_init(), and
btt_maplocks_init() is not freed on some discover_arenas() error
paths. This leaks memory when arena discovery fails.

Add the missing kfree() calls to release the allocations before
returning an error.

[ as: commit message and log edits ]

The Linux kernel CVE team has assigned CVE-2026-72223 to this issue.


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

	Issue introduced in 4.2 with commit 5212e11fde4d40fa627668b4f2222d20db488f71 and fixed in 5.10.261 with commit 2d0364937550a7b3e2592629c2a68753ac020b28
	Issue introduced in 4.2 with commit 5212e11fde4d40fa627668b4f2222d20db488f71 and fixed in 5.15.212 with commit eeb95774bc79268e2b78ebf01d8781560b5bd671
	Issue introduced in 4.2 with commit 5212e11fde4d40fa627668b4f2222d20db488f71 and fixed in 6.1.178 with commit 7563f69caa9143a491d5f26e563255c734751545
	Issue introduced in 4.2 with commit 5212e11fde4d40fa627668b4f2222d20db488f71 and fixed in 6.6.145 with commit 0b0d9404951aacc9717aa61e77af4a6e9e8f8249
	Issue introduced in 4.2 with commit 5212e11fde4d40fa627668b4f2222d20db488f71 and fixed in 6.12.97 with commit 873ced7f345e99f7ee16f9ff226515580332ecc4
	Issue introduced in 4.2 with commit 5212e11fde4d40fa627668b4f2222d20db488f71 and fixed in 6.18.40 with commit 30d490bb2c4cd220e7dedf862ab6a09eb5dcbad5
	Issue introduced in 4.2 with commit 5212e11fde4d40fa627668b4f2222d20db488f71 and fixed in 7.1.5 with commit ba59b96d8d21dc8729fca44a022ca5919c1848c9
	Issue introduced in 4.2 with commit 5212e11fde4d40fa627668b4f2222d20db488f71 and fixed in 7.2-rc1 with commit 13fe4cd9ddd0aacb7777812328be525a11ea3fea

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-2026-72223
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:
	drivers/nvdimm/btt.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/2d0364937550a7b3e2592629c2a68753ac020b28
	https://git.kernel.org/stable/c/eeb95774bc79268e2b78ebf01d8781560b5bd671
	https://git.kernel.org/stable/c/7563f69caa9143a491d5f26e563255c734751545
	https://git.kernel.org/stable/c/0b0d9404951aacc9717aa61e77af4a6e9e8f8249
	https://git.kernel.org/stable/c/873ced7f345e99f7ee16f9ff226515580332ecc4
	https://git.kernel.org/stable/c/30d490bb2c4cd220e7dedf862ab6a09eb5dcbad5
	https://git.kernel.org/stable/c/ba59b96d8d21dc8729fca44a022ca5919c1848c9
	https://git.kernel.org/stable/c/13fe4cd9ddd0aacb7777812328be525a11ea3fea