Subject: CVE-2024-47755: nvdimm: Fix devs leaks in scan_labels()

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

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

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

nvdimm: Fix devs leaks in scan_labels()

scan_labels() leaks memory when label scanning fails and it falls back
to just creating a default "seed" namespace for userspace to configure.
Root can force the kernel to leak memory.

Allocate the minimum resources unconditionally and release them when
unneeded to avoid the memory leak.

A kmemleak reports:
unreferenced object 0xffff88800dda1980 (size 16):
  comm "kworker/u10:5", pid 69, jiffies 4294671781
  hex dump (first 16 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc 0):
    [<00000000c5dea560>] __kmalloc+0x32c/0x470
    [<000000009ed43c83>] nd_region_register_namespaces+0x6fb/0x1120 [libnvdimm]
    [<000000000e07a65c>] nd_region_probe+0xfe/0x210 [libnvdimm]
    [<000000007b79ce5f>] nvdimm_bus_probe+0x7a/0x1e0 [libnvdimm]
    [<00000000a5f3da2e>] really_probe+0xc6/0x390
    [<00000000129e2a69>] __driver_probe_device+0x78/0x150
    [<000000002dfed28b>] driver_probe_device+0x1e/0x90
    [<00000000e7048de2>] __device_attach_driver+0x85/0x110
    [<0000000032dca295>] bus_for_each_drv+0x85/0xe0
    [<00000000391c5a7d>] __device_attach+0xbe/0x1e0
    [<0000000026dabec0>] bus_probe_device+0x94/0xb0
    [<00000000c590d936>] device_add+0x656/0x870
    [<000000003d69bfaa>] nd_async_device_register+0xe/0x50 [libnvdimm]
    [<000000003f4c52a4>] async_run_entry_fn+0x2e/0x110
    [<00000000e201f4b0>] process_one_work+0x1ee/0x600
    [<000000006d90d5a9>] worker_thread+0x183/0x350

The Linux kernel CVE team has assigned CVE-2024-47755 to this issue.

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

	Issue introduced in 4.2 with commit 1b40e09a1232 and fixed in 6.1.113 with commit 45db20bdb569
	Issue introduced in 4.2 with commit 1b40e09a1232 and fixed in 6.6.54 with commit 18a672c62d73
	Issue introduced in 4.2 with commit 1b40e09a1232 and fixed in 6.10.13 with commit 939053737edb
	Issue introduced in 4.2 with commit 1b40e09a1232 and fixed in 6.11.2 with commit cdf0dfb3d183
	Issue introduced in 4.2 with commit 1b40e09a1232 and fixed in 6.12-rc1 with commit 62c2aa6b1f56

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-2024-47755
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/namespace_devs.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/45db20bdb5695d06478d35e05fb2550441bed890
	https://git.kernel.org/stable/c/18a672c62d735744c6340eb3f5e58934a5d34cf2
	https://git.kernel.org/stable/c/939053737edb49ba5bdc5846acb45f11d15b7ab4
	https://git.kernel.org/stable/c/cdf0dfb3d183bbe0d0b6a6622c53d105074ad384
	https://git.kernel.org/stable/c/62c2aa6b1f565d2fc1ec11a6e9e8336ce37a6426