Riskcovery

CVE-2026-43364

ublk: fix NULL pointer dereference in ublk_ctrl_set_size()

State
Published
Severity
Not scored
Published
May 8, 2026
Updated
May 11, 2026
Reserved
May 1, 2026

Read the record on cve.org

Description

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • 98b995660bff011d8e00af03abd74ac7d1ac1390 to before f13fe6794726755a43090cb680c4c58cea6aa5f1Affected
  • 98b995660bff011d8e00af03abd74ac7d1ac1390 to before c28d945bfa92e15147e93b73f95345b9bec979b0Affected
  • 98b995660bff011d8e00af03abd74ac7d1ac1390 to before 25966fc097691e5c925ad080f64a2f19c5fd940aAffected
LinuxLinux
  • 6.16Affected
  • before 6.16Not affected
  • 6.18.20 through 6.18.*Not affected
  • 6.19.9 through 6.19.*Not affected
  • 7.0 and laterNot affected

References

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