CVE-2026-74472
Received
Received - Intake
ublk Kernel Memory Corruption in Linux Kernel
Vulnerability report for CVE-2026-74472, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-08-15
Last updated on: 2026-08-15
Assigner: kernel.org
Description
Description
In 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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
Currently, no data is known.
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
