CVE-2025-38300 in Linux
Summary
by MITRE • 07/10/2025
In the Linux kernel, the following vulnerability has been resolved:
crypto: sun8i-ce-cipher - fix error handling in sun8i_ce_cipher_prepare()
Fix two DMA cleanup issues on the error path in sun8i_ce_cipher_prepare():
1] If dma_map_sg() fails for areq->dst, the device driver would try to free DMA memory it has not allocated in the first place. To fix this, on the "theend_sgs" error path, call dma unmap only if the corresponding dma map was successful.
2] If the dma_map_single() call for the IV fails, the device driver would try to free an invalid DMA memory address on the "theend_iv" path: ------------[ cut here ]------------
DMA-API: sun8i-ce 1904000.crypto: device driver tries to free an invalid DMA memory address WARNING: CPU: 2 PID: 69 at kernel/dma/debug.c:968 check_unmap+0x123c/0x1b90 Modules linked in: skcipher_example(O+) CPU: 2 UID: 0 PID: 69 Comm: 1904000.crypto- Tainted: G O 6.15.0-rc3+ #24 PREEMPT Tainted: [O]=OOT_MODULE
Hardware name: OrangePi Zero2 (DT) pc : check_unmap+0x123c/0x1b90 lr : check_unmap+0x123c/0x1b90 ... Call trace: check_unmap+0x123c/0x1b90 (P) debug_dma_unmap_page+0xac/0xc0 dma_unmap_page_attrs+0x1f4/0x5fc sun8i_ce_cipher_do_one+0x1bd4/0x1f40 crypto_pump_work+0x334/0x6e0 kthread_worker_fn+0x21c/0x438 kthread+0x374/0x664 ret_from_fork+0x10/0x20 ---[ end trace 0000000000000000 ]---
To fix this, check for !dma_mapping_error() before calling dma_unmap_single() on the "theend_iv" path.
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Analysis
by VulDB Data Team • 12/19/2025
The vulnerability CVE-2025-38300 affects the Linux kernel's cryptographic subsystem, specifically within the sun8i-ce-cipher driver that handles cipher operations for Allwinner SoC devices. This issue represents a critical error handling flaw that can lead to system instability and potential security implications through improper memory management during cryptographic operations. The vulnerability manifests in the sun8i_ce_cipher_prepare() function where incorrect DMA cleanup procedures are executed on error paths, creating opportunities for invalid memory operations.
The technical flaw stems from improper conditional checks during the error handling sequence of DMA memory operations within the cryptographic engine driver. When dma_map_sg() fails for the destination buffer areq->dst, the driver attempts to unmap DMA memory that was never successfully mapped, leading to a scenario where the device driver tries to free memory it has not allocated. This violates fundamental DMA memory management principles and creates a potential for system crashes or memory corruption. Additionally, when dma_map_single() fails for the Initialization Vector (IV) buffer, the driver attempts to free an invalid DMA memory address, triggering kernel warnings and potentially causing system panics as demonstrated by the specific error trace showing DMA-API violations.
The operational impact of this vulnerability extends beyond simple system crashes to encompass potential data integrity issues and denial of service conditions within cryptographic operations. The improper error handling can affect any application or system component relying on the sun8i-ce cryptographic engine for cipher operations, particularly in embedded systems running on Allwinner SoC platforms such as the OrangePi Zero2. This vulnerability directly relates to CWE-459, which addresses incomplete cleanup issues in software systems, and can be categorized under ATT&CK technique T1499.200 focusing on virtualization and container abuse through kernel-level exploits.
Mitigation strategies for CVE-2025-38300 involve implementing proper conditional checks before DMA memory cleanup operations, specifically ensuring that dma_unmap_page() is only called when corresponding dma_map_sg() operations were successful, and that dma_unmap_single() is only invoked after confirming that dma_map_single() did not return an error condition through dma_mapping_error() checks. The fix requires modifying the error handling paths in sun8i_ce_cipher_prepare() to maintain proper synchronization between mapping and unmapping operations, preventing invalid memory operations that could compromise system stability. System administrators should prioritize applying kernel updates containing this fix, particularly in environments where cryptographic operations are frequently performed and system reliability is paramount, as the vulnerability could be exploited to cause persistent system instability or denial of service conditions.