CVE-2026-89515

A flaw was found in the Linux kernel's SCSI core component. When processing data transfers using scatter-gather lists, the system does not properly initialize padding bytes for unaligned data elements. This can result in the exposure of uninitialized memory, potentially allowing a local attacker to read sensitive information or cause a system crash (denial of service).

A moderate-impact flaw was found in the Linux kernel's SCSI core subsystem, affecting the Red Hat Enterprise Linux kernel and kernel-rt packages. When a SCSI command issued through the local SG_IO ioctl path uses a user-supplied data buffer whose last scatter-gather element is unaligned, scsi_alloc_sgtables() pads the transfer with pad_len bytes that are left uninitialized before the buffer is mapped for DMA. As a result, a local user with access to SCSI block devices could expose uninitialized kernel memory (potential information disclosure) or cause a system crash (denial of service). Red Hat assessed this flaw as Moderate severity with a CVSS 3.1 score of 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H); this score reflects the availability impact of a kernel crash, while the CVE description additionally notes the theoretical possibility of reading sensitive information from the exposed padding bytes. The currently tracked Red Hat product relationships for the kernel component are affected.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.