Linux Kernel CVE-2026-72440

The affected component is the md/raid1 driver (Multiple Device, RAID-1 mirroring) in the Linux kernel, covered by CPE cpe:2.3:a:linux:linux:*. The root cause is a resource management defect structurally equivalent to CWE-772 (Missing Release of Resource after Effective Lifetime): raid1_make_request() calls md_write_start() to acquire a writes_pending reference before delegating to raid1_write_request(), but several early-return failure paths within raid1_write_request() complete the bio and return without invoking md_write_end(), leaving the reference permanently held. A second independent leak occurs when wait_blocked_rdev() fails after wait_barrier() has already succeeded - the barrier reference is never released via allow_barrier(), leaving the barrier count permanently elevated. The fix introduces a return status from raid1_write_request() enabling raid1_make_request() to call md_write_end() on failure, and adds an explicit allow_barrier() call on the affected error path. Both stable-tree fixes are published at git.kernel.org.