Bug 2536711 (CVE-2026-90385)

Summary:	CVE-2026-90385 kernel: md/raid1: create serial pool adding rdev to array with serialize_policy=1
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel. When a new storage device is added to an existing RAID1 array with a specific serialization policy enabled, a critical internal object is not properly initialized. This oversight can lead to a system crash, resulting in a Denial of Service (DoS) for the affected system.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-17 19:13:11 UTC

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

md/raid1: create serial pool adding rdev to array with serialize_policy=1

The following bug has been observed with kernel 7.1.3 after adding a new
rdev to an existing RAID1 array with serialize_policy enabled:

  Oops: 0002 [#1]
  CPU: 0 UID: 0 PID: 19639 Comm: ext4lazyinit Not tainted 7.1.3-1-default
  RIP: _raw_spin_lock_irqsave+0x27/0x50
  CR2: 0000000000004960
  Call Trace:
   wait_for_serialization+0xb9/0x260 [raid1]
   raid1_make_request+0x762/0xaff [raid1]
   md_handle_request+0x1c9/0x2e0 [md_mod]

The raid1.c code calls wait_for_serialization() if the MD_SERIALIZE_POLICY
is set, and wait_for_serialization assumes that rdev->serial is
initialized. Normally this will be the case for arrays that have
the serialize_policy sysfs attribute set to 1.

But when a new rdev is added to an existing array in bind_rdev_to_array(),
the condition at mddev_create_serial_pool() causes creation of rdev->serial
to be skipped. Fix it.

Comment 1 gkamathe 2026-09-21 07:15:53 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90385.mbox