linux-cve-announce - CVE-2022-50434: blk-mq: fix possible memleak when register 'hctx' failed

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <2025100159-CVE-2022-50434-e4db@gregkh>
Date: Wed,  1 Oct 2025 13:42:07 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2022-50434: blk-mq: fix possible memleak when register 'hctx' failed

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

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

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

blk-mq: fix possible memleak when register 'hctx' failed

There's issue as follows when do fault injection test:
unreferenced object 0xffff888132a9f400 (size 512):
  comm "insmod", pid 308021, jiffies 4324277909 (age 509.733s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 08 f4 a9 32 81 88 ff ff  ...........2....
    08 f4 a9 32 81 88 ff ff 00 00 00 00 00 00 00 00  ...2............
  backtrace:
    [<00000000e8952bb4>] kmalloc_node_trace+0x22/0xa0
    [<00000000f9980e0f>] blk_mq_alloc_and_init_hctx+0x3f1/0x7e0
    [<000000002e719efa>] blk_mq_realloc_hw_ctxs+0x1e6/0x230
    [<000000004f1fda40>] blk_mq_init_allocated_queue+0x27e/0x910
    [<00000000287123ec>] __blk_mq_alloc_disk+0x67/0xf0
    [<00000000a2a34657>] 0xffffffffa2ad310f
    [<00000000b173f718>] 0xffffffffa2af824a
    [<0000000095a1dabb>] do_one_initcall+0x87/0x2a0
    [<00000000f32fdf93>] do_init_module+0xdf/0x320
    [<00000000cbe8541e>] load_module+0x3006/0x3390
    [<0000000069ed1bdb>] __do_sys_finit_module+0x113/0x1b0
    [<00000000a1a29ae8>] do_syscall_64+0x35/0x80
    [<000000009cd878b0>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Fault injection context as follows:
 kobject_add
 blk_mq_register_hctx
 blk_mq_sysfs_register
 blk_register_queue
 device_add_disk
 null_add_dev.part.0 [null_blk]

As 'blk_mq_register_hctx' may already add some objects when failed halfway,
but there isn't do fallback, caller don't know which objects add failed.
To solve above issue just do fallback when add objects failed halfway in
'blk_mq_register_hctx'.

The Linux kernel CVE team has assigned CVE-2022-50434 to this issue.


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

	Fixed in 4.9.337 with commit 654870789c3c1b9763316ef1c71d7a449127b175
	Fixed in 4.14.303 with commit cb186eb47fb9dd327bdefa15f0c5fc55c53a40dd
	Fixed in 4.19.270 with commit 02bc8bc6eab03c84373281b85cb6e98747172ff7
	Fixed in 5.4.229 with commit 87fd18016a47ea8ae12641377a390172c4aa97a7
	Fixed in 5.10.163 with commit e8022da1fa2fdf2fa204b445dd3354e7a66d085a
	Fixed in 5.15.86 with commit eff45bfbc25a2509a6362dea6e699e14083c693c
	Fixed in 6.0.16 with commit 4b7fafa5f39b15c3a6ca3b95e534d05d6904cc95
	Fixed in 6.1.2 with commit 33e8a3f61814ea30615d0fafaf50477975d6c1ca
	Fixed in 6.2 with commit 4b7a21c57b14fbcd0e1729150189e5933f5088e9

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-2022-50434
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:
	block/blk-mq-sysfs.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/654870789c3c1b9763316ef1c71d7a449127b175
	https://git.kernel.org/stable/c/cb186eb47fb9dd327bdefa15f0c5fc55c53a40dd
	https://git.kernel.org/stable/c/02bc8bc6eab03c84373281b85cb6e98747172ff7
	https://git.kernel.org/stable/c/87fd18016a47ea8ae12641377a390172c4aa97a7
	https://git.kernel.org/stable/c/e8022da1fa2fdf2fa204b445dd3354e7a66d085a
	https://git.kernel.org/stable/c/eff45bfbc25a2509a6362dea6e699e14083c693c
	https://git.kernel.org/stable/c/4b7fafa5f39b15c3a6ca3b95e534d05d6904cc95
	https://git.kernel.org/stable/c/33e8a3f61814ea30615d0fafaf50477975d6c1ca
	https://git.kernel.org/stable/c/4b7a21c57b14fbcd0e1729150189e5933f5088e9