GHSA-7JG9-VHJ9-WG56
Vulnerability from github – Published: 2026-08-15 15:30 – Updated: 2026-08-19 18:32In the Linux kernel, the following vulnerability has been resolved:
ublk: reset kernel-owned dev_info fields in ublk_ctrl_add_dev()
ublk_ctrl_add_dev() memcpy()s the userspace ublksrv_ctrl_dev_info into ub->dev_info and then fixes up the fields the driver owns, but misses ->state and ->ublksrv_pid.
A device added with ->state = UBLK_S_DEV_LIVE passes the "->state != UBLK_S_DEV_DEAD" test that ublk_stop_dev_unlocked() uses as its proxy for "a disk is attached", while ->ub_disk is still NULL, so DEL_DEV right after ADD_DEV oopses in del_gendisk(). UBLK_S_DEV_QUIESCED plus UBLK_F_USER_RECOVERY dies one step earlier, in ublk_force_abort_dev(). A poisoned ->state also gets START_USER_RECOVERY and the char device read/write path onto a device that was never started, and wedges START_DEV at -EEXIST. A poisoned ->ublksrv_pid just makes GET_DEV_INFO report an unrelated task as the ublk server.
Reset both after the memcpy(), as ublk_detach_disk() does. Userspace only ever reads these back, so correcting them silently breaks nothing.
ADD_DEV has copied ->state in unsanitized since ublk was merged, but back then it was harmless: the gendisk was allocated during ADD_DEV, and both teardown and the START_DEV -EEXIST check keyed off disk_live() rather than ->state. The oops became reachable once the disk allocation moved to START_DEV and those checks switched to ->state.
{
"affected": [],
"aliases": [
"CVE-2026-74472"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T13:17:51Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nublk: reset kernel-owned dev_info fields in ublk_ctrl_add_dev()\n\nublk_ctrl_add_dev() memcpy()s the userspace ublksrv_ctrl_dev_info into\nub-\u003edev_info and then fixes up the fields the driver owns, but misses\n-\u003estate and -\u003eublksrv_pid.\n\nA device added with -\u003estate = UBLK_S_DEV_LIVE passes the\n\"-\u003estate != UBLK_S_DEV_DEAD\" test that ublk_stop_dev_unlocked() uses as its\nproxy for \"a disk is attached\", while -\u003eub_disk is still NULL, so DEL_DEV\nright after ADD_DEV oopses in del_gendisk(). UBLK_S_DEV_QUIESCED plus\nUBLK_F_USER_RECOVERY dies one step earlier, in ublk_force_abort_dev(). A\npoisoned -\u003estate also gets START_USER_RECOVERY and the char device\nread/write path onto a device that was never started, and wedges START_DEV\nat -EEXIST. A poisoned -\u003eublksrv_pid just makes GET_DEV_INFO report an\nunrelated task as the ublk server.\n\nReset both after the memcpy(), as ublk_detach_disk() does. Userspace only\never reads these back, so correcting them silently breaks nothing.\n\nADD_DEV has copied -\u003estate in unsanitized since ublk was merged, but back\nthen it was harmless: the gendisk was allocated during ADD_DEV, and both\nteardown and the START_DEV -EEXIST check keyed off disk_live() rather than\n-\u003estate. The oops became reachable once the disk allocation moved to\nSTART_DEV and those checks switched to -\u003estate.",
"id": "GHSA-7jg9-vhj9-wg56",
"modified": "2026-08-19T18:32:28Z",
"published": "2026-08-15T15:30:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74472"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/127033b79383a3e78361d7e971588aa8849f5124"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/205feb72e5beb3140e4e1403b6cff30cf739bab9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/787c944502e7e63d20a9201bada77e0dd924f458"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b67ce16b26ad0f14cfd6071013840aa95f823bea"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e65848e4ce352bac9e3465099354c8b8f845391f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ee41b00858ca65b4428e99efe39a4277c1f043d2"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.