Unchecked Return Value in Linux kernel - CVE-2026-90324

Vulnerability identifier: #VU151159

CSH Severity: Low

CVSS v4: 0 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90324

CWE-ID: CWE-252

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to trigger I/O processing with an uninitialized iov_iter.

The vulnerability exists due to an unchecked return value in the ublk_map_io and ublk_unmap_io functions when processing an I/O buffer address supplied by a userspace ublk server. A local user can operate a userspace ublk server and provide an address range outside the allowed user address space to trigger I/O processing with an uninitialized iov_iter.

Linux kernel
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux (Debian package)

Install security update from vendor's repository.

linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17
linux (Debian package) - update to 6.12.115-2

• https://git.kernel.org/stable/c/0121c84adb6a4cd6f7560b5895bd88f9899bbc1f
• https://git.kernel.org/stable/c/3831568792af75b6523fa93bb91560e29189cf55
• https://git.kernel.org/stable/c/5ac6019cb78e98c9608fda72726b36ddf8474dd7

• Unchecked Return Value in Linux kernel block driver
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more