From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-89552: params: fix charp corruption on allocation failure
Date: Fri, 11 Sep 2026 21:44:01 +0200 [thread overview]
Message-ID: <2026091121-CVE-2026-89552-e2ca@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
params: fix charp corruption on allocation failure
param_set_charp() stores charp parameters in allocated memory after slab is
available, and releases the previous value when the parameter is updated.
The previous value is released before the replacement allocation succeeds.
If kmalloc_parameter() fails, the setter returns -ENOMEM with the parameter
left as NULL.
Failing zswap's compressor update before zswap is initialized can later
trigger:
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:strcmp+0x10/0x30
Call Trace:
zswap_setup+0x3b1/0x490
zswap_enabled_param_set+0x5b/0xa0
param_attr_store+0x93/0xe0
module_attr_store+0x1c/0x30
kernfs_fop_write_iter+0x116/0x1f0
Allocate and copy the replacement first, then replace the parameter value
only after allocation succeeds.
The Linux kernel CVE team has assigned CVE-2026-89552 to this issue.
Affected and fixed versions
===========================
Issue introduced in 2.6.30 with commit e180a6b7759a99a28cbcce3547c4c80822cb6c2a and fixed in 6.12.109 with commit 614f873268c5b172804c9af6639bd17b7e1e2359
Issue introduced in 2.6.30 with commit e180a6b7759a99a28cbcce3547c4c80822cb6c2a and fixed in 6.18.50 with commit 704ecd010d4a9b33160e40b74eb402f6b86a18e0
Issue introduced in 2.6.30 with commit e180a6b7759a99a28cbcce3547c4c80822cb6c2a and fixed in 7.2.4 with commit 0d8e2404925a0607ffec79a53170715a46936896
Issue introduced in 2.6.30 with commit e180a6b7759a99a28cbcce3547c4c80822cb6c2a and fixed in 7.3-rc1 with commit 3dfaae04243cde460d82dfc2a7dd0bb6664d20ae
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-2026-89552
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:
kernel/params.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/614f873268c5b172804c9af6639bd17b7e1e2359
https://git.kernel.org/stable/c/704ecd010d4a9b33160e40b74eb402f6b86a18e0
https://git.kernel.org/stable/c/0d8e2404925a0607ffec79a53170715a46936896
https://git.kernel.org/stable/c/3dfaae04243cde460d82dfc2a7dd0bb6664d20ae
reply other threads:[~2026-09-11 19:56 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=2026091121-CVE-2026-89552-e2ca@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.