CVE-2026-43364 (GCVE-0-2026-43364)

Vulnerability from cvelistv5 – Published: 2026-05-08 14:21 – Updated: 2026-05-11 22:23
VLAI
Title
ublk: fix NULL pointer dereference in ublk_ctrl_set_size()
Summary
In the Linux kernel, the following vulnerability has been resolved: ublk: fix NULL pointer dereference in ublk_ctrl_set_size() ublk_ctrl_set_size() unconditionally dereferences ub->ub_disk via set_capacity_and_notify() without checking if it is NULL. ub->ub_disk is NULL before UBLK_CMD_START_DEV completes (it is only assigned in ublk_ctrl_start_dev()) and after UBLK_CMD_STOP_DEV runs (ublk_detach_disk() sets it to NULL). Since the UBLK_CMD_UPDATE_SIZE handler performs no state validation, a user can trigger a NULL pointer dereference by sending UPDATE_SIZE to a device that has been added but not yet started, or one that has been stopped. Fix this by checking ub->ub_disk under ub->mutex before dereferencing it, and returning -ENODEV if the disk is not available.
Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6640 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 98b995660bff011d8e00af03abd74ac7d1ac1390 , < f13fe6794726755a43090cb680c4c58cea6aa5f1 (git)
Affected: 98b995660bff011d8e00af03abd74ac7d1ac1390 , < c28d945bfa92e15147e93b73f95345b9bec979b0 (git)
Affected: 98b995660bff011d8e00af03abd74ac7d1ac1390 , < 25966fc097691e5c925ad080f64a2f19c5fd940a (git)
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Linux Linux Affected: 6.16
Unaffected: 0 , < 6.16 (semver)
Unaffected: 6.18.20 , ≤ 6.18.* (semver)
Unaffected: 6.19.9 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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}



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