CVE-2026-90385 md/raid1: create serial pool adding rdev to array with serialize_policy=1
A null pointer dereference in the Linux kernel RAID1 driver causes a system crash when adding a device to an array with serialization enabled.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90385?
CVE-2026-90385 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-90385?
How do I fix CVE-2026-90385?
Apply the vendor's patch.
Is CVE-2026-90385 being exploited?
There is no known exploitation of CVE-2026-90385 in the wild and no public exploit code.
Sources
Also known as AZL-102096, BELL-CVE-2026-90385, DEBIAN-CVE-2026-90385, GHSA-6jq9-46p7-p377, UBUNTU-CVE-2026-90385.