From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2022-49902: block: Fix possible memory leak for rq_wb on add_disk failure
Date: Thu, 1 May 2025 16:11:32 +0200 [thread overview]
Message-ID: <2025050102-CVE-2022-49902-59fe@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
block: Fix possible memory leak for rq_wb on add_disk failure
kmemleak reported memory leaks in device_add_disk():
kmemleak: 3 new suspected memory leaks
unreferenced object 0xffff88800f420800 (size 512):
comm "modprobe", pid 4275, jiffies 4295639067 (age 223.512s)
hex dump (first 32 bytes):
04 00 00 00 08 00 00 00 01 00 00 00 00 00 00 00 ................
00 e1 f5 05 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000d3662699>] kmalloc_trace+0x26/0x60
[<00000000edc7aadc>] wbt_init+0x50/0x6f0
[<0000000069601d16>] wbt_enable_default+0x157/0x1c0
[<0000000028fc393f>] blk_register_queue+0x2a4/0x420
[<000000007345a042>] device_add_disk+0x6fd/0xe40
[<0000000060e6aab0>] nbd_dev_add+0x828/0xbf0 [nbd]
...
It is because the memory allocated in wbt_enable_default() is not
released in device_add_disk() error path.
Normally, these memory are freed in:
del_gendisk()
rq_qos_exit()
rqos->ops->exit(rqos);
wbt_exit()
So rq_qos_exit() is called to free the rq_wb memory for wbt_init().
However in the error path of device_add_disk(), only
blk_unregister_queue() is called and make rq_wb memory leaked.
Add rq_qos_exit() to the error path to fix it.
The Linux kernel CVE team has assigned CVE-2022-49902 to this issue.
Affected and fixed versions
===========================
Issue introduced in 5.15 with commit 83cbce9574462c6b4eed6797bdaf18fae6859ab3 and fixed in 5.15.78 with commit 4e68c5da60cd79950bd56287ae80b39d6261f995
Issue introduced in 5.15 with commit 83cbce9574462c6b4eed6797bdaf18fae6859ab3 and fixed in 6.0.8 with commit 528677d3b4af985445bd4ac667485ded1ed11220
Issue introduced in 5.15 with commit 83cbce9574462c6b4eed6797bdaf18fae6859ab3 and fixed in 6.1 with commit fa81cbafbf5764ad5053512152345fab37a1fe18
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-2022-49902
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/genhd.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/4e68c5da60cd79950bd56287ae80b39d6261f995
https://git.kernel.org/stable/c/528677d3b4af985445bd4ac667485ded1ed11220
https://git.kernel.org/stable/c/fa81cbafbf5764ad5053512152345fab37a1fe18
reply other threads:[~2025-05-01 14:19 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2025050102-CVE-2022-49902-59fe@gregkh \
--to=gregkh@linuxfoundation.org \
--cc=cve@kernel.org \
--cc=gregkh@kernel.org \
--cc=linux-cve-announce@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.