Bug 2464418 (CVE-2026-43055)

Summary:	CVE-2026-43055 kernel: scsi: target: file: Use kzalloc_flex for aio_cmd
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's SCSI target file module. When a write command is executed, the `aio_cmd->iocb` for the `ki_write_stream` is not initialized. This can lead to an incorrect `ki_write_stream` value, causing unintended write failures in the block device. This vulnerability can result in a Denial of Service (DoS) for applications attempting to write data.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-05-01 15:05:45 UTC

In the Linux kernel, the following vulnerability has been resolved:

scsi: target: file: Use kzalloc_flex for aio_cmd

The target_core_file doesn't initialize the aio_cmd->iocb for the
ki_write_stream. When a write command fd_execute_rw_aio() is executed,
we may get a bogus ki_write_stream value, causing unintended write
failure status when checking iocb->ki_write_stream > max_write_streams
in the block device.

Let's just use kzalloc_flex when allocating the aio_cmd and let
ki_write_stream=0 to fix this issue.

Comment 1 Keith Grant 2026-05-01 18:57:01 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050108-CVE-2026-43055-5bb1@gregkh/T