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

Summary

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.

Timeline

1. Sep 17, 2026, 4:09 PM UTCCVE published
2. Oct 21, 2026, 12:51 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 69b00b5bb23552d43e8bbed73ef6624604bb94a2 · fixed in 0b187e14dab458d54425fc400f1e1e8d481d9bcf; From 69b00b5bb23552d43e8bbed73ef6624604bb94a2 · fixed in f9e4364449f7ca6917f3599eb32064dba5b7b147; From 69b00b5bb23552d43e8bbed73ef6624604bb94a2 · fixed in 37f11973c3eb72a5eb061082cad529bb6939c24f; From 69b00b5bb23552d43e8bbed73ef6624604bb94a2 · fixed in c02d675e81468003e4f2253b616c53729070d712; From 69b00b5bb23552d43e8bbed73ef6624604bb94a2 · fixed in 140234b2380ffb8ffb0cfc46fee0e822f43adef7

• Linux Linux

  5.6

• KernelLinux

  From 5.6.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6

References 5