CVE Catalog

CVE-2026-74555

Low risk· EPSS 5%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.16%

5th percentile - higher than 5% of all known CVEs

Summary

In the Linux kernel SCSI libsas subsystem, there is a deadlock during host adapter resume and a race condition in the hisi_sas driver related to disk wake-up. The issue appeared after a change that skipped draining the event workqueue, causing disks to send I/O to a suspended controller and get disabled. The fix moves the PHYE_RESUME_TIMEOUT notification after the workqueue drain, eliminating the deadlock and restoring safe resume behavior.

Risk Assessment

Organizations may experience disk failures and data loss on systems using SAS controllers (e.g., hisi_sas) during resume from suspend. The deadlock can also block the entire SCSI subsystem, leading to service unavailability.

Recommendation

Apply the kernel patch containing this fix immediately and update to a kernel version where the fix is available. Monitor distribution security advisories for backports.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: scsi: libsas: Fix HA resume deadlock and hisi_sas disk-wake race Commit fbefe22811c3 ("scsi: libsas: Don't always drain event workqueue for HA resume") introduced sas_resume_ha_no_sync() to avoid a deadlock: the PHYE_RESUME_TIMEOUT handler, running on the HA event workqueue, calls sas_deform_port() -> sas_destruct_devices(), which removes SCSI devices and waits for the host to become runtime-active. But the host cannot resume until sas_resume_ha() -> sas_drain_work() returns, and the drain is blocked on that very handler. However skipping the drain reintroduces a race: hisi_sas returns from resume before all PHY UP work and libsas discovery work finish. The controller may then autosuspend while disks are still waking up. The disks issue IO to a suspended controller, the IO fails, and the disks get disabled. Fix the deadlock at its source by moving the PHYE_RESUME_TIMEOUT notification to after sas_drain_work(). By then the host resume is about to complete, so device removal through device_link no longer blocks on the resume and the cycle is broken. With the deadlock gone, restore sas_resume_ha() (the draining variant) in hisi_sas and remove sas_resume_ha_no_sync(). The reorder is safe for the other libsas consumers (isci, pm8001, aic94xx, mvsas). During suspend, sas_suspend_devices() calls sas_notify_lldd_dev_gone() for each device, which sets dev->lldd_dev to NULL. When scsi_unblock_requests re-enables I/O in resume, any I/O to a timed-out phy's disk is immediately rejected by the LLDD before reaching hardware: isci returns SAS_DEVICE_UNKNOWN (mapped to DID_BAD_TARGET), and pm8001 returns SAS_PHY_DOWN (mapped to DID_NO_CONNECT). Both complete directly via scsi_done() without entering SCSI EH. This is identical in both the old and new ordering since lldd_dev_gone runs during suspend, before resume. The reorder only affects when the PHYE_RESUME_TIMEOUT handler runs (synchronized by sas_drain_work() vs. asynchronous after resume returns), not whether I/O can reach the device. aic94xx and mvsas do not register any PM ops and never reach this code path.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS