CVE-2023-53256 in Linux
Summary
by MITRE • 09/15/2025
In the Linux kernel, the following vulnerability has been resolved:
firmware: arm_ffa: Fix FFA device names for logical partitions
Each physical partition can provide multiple services each with UUID. Each such service can be presented as logical partition with a unique combination of VM ID and UUID. The number of distinct UUID in a system will be less than or equal to the number of logical partitions.
However, currently it fails to register more than one logical partition or service within a physical partition as the device name contains only VM ID while both VM ID and UUID are maintained in the partition information. The kernel complains with the below message:
| sysfs: cannot create duplicate filename '/devices/arm-ffa-8001' | CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.3.0-rc7 #8 | Hardware name: FVP Base RevC (DT) | Call trace: | dump_backtrace+0xf8/0x118 | show_stack+0x18/0x24 | dump_stack_lvl+0x50/0x68 | dump_stack+0x18/0x24 | sysfs_create_dir_ns+0xe0/0x13c | kobject_add_internal+0x220/0x3d4 | kobject_add+0x94/0x100 | device_add+0x144/0x5d8 | device_register+0x20/0x30 | ffa_device_register+0x88/0xd8 | ffa_setup_partitions+0x108/0x1b8 | ffa_init+0x2ec/0x3a4 | do_one_initcall+0xcc/0x240 | do_initcall_level+0x8c/0xac | do_initcalls+0x54/0x94 | do_basic_setup+0x1c/0x28 | kernel_init_freeable+0x100/0x16c | kernel_init+0x20/0x1a0 | ret_from_fork+0x10/0x20 | kobject_add_internal failed for arm-ffa-8001 with -EEXIST, don't try to | register things with the same name in the same directory. | arm_ffa arm-ffa: unable to register device arm-ffa-8001 err=-17 | ARM FF-A: ffa_setup_partitions: failed to register partition ID 0x8001
By virtue of being random enough to avoid collisions when generated in a distributed system, there is no way to compress UUID keys to the number of bits required to identify each. We can eliminate '-' in the name but it is not worth eliminating 4 bytes and add unnecessary logic for doing that. Also v1.0 doesn't provide the UUID of the partitions which makes it hard to use the same for the device name.
So to keep it simple, let us alloc an ID using ida_alloc() and append the same to "arm-ffa" to make up a unique device name. Also stash the id value in ffa_dev to help freeing the ID later when the device is destroyed.
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Analysis
by VulDB Data Team • 01/11/2026
The vulnerability identified as CVE-2023-53256 resides within the Linux kernel's firmware handling subsystem, specifically in the arm_ffa module responsible for managing Firmware Framework for Arm (FF-A) device interactions. This issue affects systems utilizing the Arm Flexible Firmware Framework architecture where physical partitions can expose multiple logical services through unique combinations of Virtual Machine IDs and Universally Unique Identifiers. The flaw manifests when attempting to register multiple logical partitions within a single physical partition, creating a scenario where device name collisions occur due to insufficient uniqueness in the naming scheme.
The technical root cause stems from the kernel's device name generation logic which only incorporates the Virtual Machine ID component into the device identifier while maintaining both VM ID and UUID information internally. This design flaw results in multiple logical partitions sharing identical device names such as 'arm-ffa-8001', causing the sysfs subsystem to reject subsequent registration attempts with the error message indicating duplicate filename creation failure. The kernel's call trace demonstrates this failure occurring during the ffa_device_register function execution within the ffa_setup_partitions initialization routine, ultimately preventing proper device registration and system functionality.
This vulnerability impacts system reliability and firmware management capabilities by preventing the proper enumeration and utilization of multiple services within a single physical partition. The failure to register additional logical partitions can lead to incomplete firmware service exposure, potentially affecting system security posture and operational integrity. The issue is particularly concerning in virtualized environments where Arm FF-A implementations are commonly deployed, as it limits the ability to fully leverage partition-based service separation and isolation mechanisms. From an operational perspective, this vulnerability may require system reboots or manual intervention to resolve device registration conflicts, disrupting normal system operations and potentially masking underlying firmware service availability issues.
The fix implemented addresses this by utilizing the ida_alloc() function to generate unique identifiers for each device registration, appending these numeric IDs to the base "arm-ffa" prefix to ensure device name uniqueness. This approach aligns with CWE-129: Improper Validation of Array Index, as it prevents the array-like collision scenario that occurred with device name generation. The solution also incorporates proper resource management by stashing the allocated ID value within the ffa_dev structure for later cleanup, following secure coding practices for resource management. This remediation follows ATT&CK technique T1547.006: System Scripting, by ensuring proper device registration and avoiding system-level failures that could otherwise require manual intervention or system restarts. The implementation maintains backward compatibility while resolving the core naming collision issue through a deterministic, unique identifier generation mechanism that prevents the duplicate device name scenario described in the vulnerability report.