SB2026050924 - NULL pointer dereference in Linux kernel block driver

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-43364)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a NULL pointer dereference in ublk_ctrl_set_size() when handling UBLK_CMD_UPDATE_SIZE requests for a device that has not yet been started or has already been stopped. A local user can send a crafted UPDATE_SIZE command to cause a denial of service.

The issue can be triggered before UBLK_CMD_START_DEV completes or after UBLK_CMD_STOP_DEV runs.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/25966fc097691e5c925ad080f64a2f19c5fd940a
• https://git.kernel.org/stable/c/c28d945bfa92e15147e93b73f95345b9bec979b0
• https://git.kernel.org/stable/c/f13fe6794726755a43090cb680c4c58cea6aa5f1