GHSA-93W9-8J8X-2PRP
Vulnerability from github – Published: 2026-08-15 15:30 – Updated: 2026-08-15 15:30In 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.
{
"affected": [],
"aliases": [
"CVE-2026-74555"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T13:18:00Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: libsas: Fix HA resume deadlock and hisi_sas disk-wake race\n\nCommit fbefe22811c3 (\"scsi: libsas: Don\u0027t always drain event workqueue\nfor HA resume\") introduced sas_resume_ha_no_sync() to avoid a deadlock:\nthe PHYE_RESUME_TIMEOUT handler, running on the HA event workqueue,\ncalls sas_deform_port() -\u003e sas_destruct_devices(), which removes SCSI\ndevices and waits for the host to become runtime-active. But the host\ncannot resume until sas_resume_ha() -\u003e sas_drain_work() returns, and the\ndrain is blocked on that very handler.\n\nHowever skipping the drain reintroduces a race: hisi_sas returns from\nresume before all PHY UP work and libsas discovery work finish. The\ncontroller may then autosuspend while disks are still waking up. The\ndisks issue IO to a suspended controller, the IO fails, and the disks\nget disabled.\n\nFix the deadlock at its source by moving the PHYE_RESUME_TIMEOUT\nnotification to after sas_drain_work(). By then the host resume is about\nto complete, so device removal through device_link no longer blocks on\nthe resume and the cycle is broken.\n\nWith the deadlock gone, restore sas_resume_ha() (the draining variant)\nin hisi_sas and remove sas_resume_ha_no_sync().\n\nThe reorder is safe for the other libsas consumers (isci, pm8001,\naic94xx, mvsas). During suspend, sas_suspend_devices() calls\nsas_notify_lldd_dev_gone() for each device, which sets dev-\u003elldd_dev to\nNULL. When scsi_unblock_requests re-enables I/O in resume, any I/O to a\ntimed-out phy\u0027s disk is immediately rejected by the LLDD before reaching\nhardware: isci returns SAS_DEVICE_UNKNOWN (mapped to DID_BAD_TARGET),\nand pm8001 returns SAS_PHY_DOWN (mapped to DID_NO_CONNECT). Both\ncomplete directly via scsi_done() without entering SCSI EH. This is\nidentical in both the old and new ordering since lldd_dev_gone runs\nduring suspend, before resume. The reorder only affects when the\nPHYE_RESUME_TIMEOUT handler runs (synchronized by sas_drain_work()\nvs. asynchronous after resume returns), not whether I/O can reach the\ndevice. aic94xx and mvsas do not register any PM ops and never reach\nthis code path.",
"id": "GHSA-93w9-8j8x-2prp",
"modified": "2026-08-15T15:30:36Z",
"published": "2026-08-15T15:30:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74555"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3dbbbf656b850c9c8de05df6ad4a1dfc6ff02845"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9e24b47ef81d43b3fb1b14294f09991640c79fcc"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b9c44a14062093e9fc2d6bddc696cfceadb482d7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c391b5899dd46485a5893696c12ae3e95a3a7325"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e50a6523a603594a6d92cdecfe11997d639410a3"
}
],
"schema_version": "1.4.0",
"severity": []
}
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