CVE-2025-38005 in Linux
Summary
by MITRE • 06/18/2025
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: ti: k3-udma: Add missing locking
Recent kernels complain about a missing lock in k3-udma.c when the lock validator is enabled:
[ 4.128073] WARNING: CPU: 0 PID: 746 at drivers/dma/ti/../virt-dma.h:169 udma_start.isra.0+0x34/0x238
[ 4.137352] CPU: 0 UID: 0 PID: 746 Comm: kworker/0:3 Not tainted 6.12.9-arm64 #28
[ 4.144867] Hardware name: pp-v12 (DT)
[ 4.148648] Workqueue: events udma_check_tx_completion
[ 4.153841] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 4.160834] pc : udma_start.isra.0+0x34/0x238
[ 4.165227] lr : udma_start.isra.0+0x30/0x238
[ 4.169618] sp : ffffffc083cabcf0
[ 4.172963] x29: ffffffc083cabcf0 x28: 0000000000000000 x27: ffffff800001b005
[ 4.180167] x26: ffffffc0812f0000 x25: 0000000000000000 x24: 0000000000000000
[ 4.187370] x23: 0000000000000001 x22: 00000000e21eabe9 x21: ffffff8000fa0670
[ 4.194571] x20: ffffff8001b6bf00 x19: ffffff8000fa0430 x18: ffffffc083b95030
[ 4.201773] x17: 0000000000000000 x16: 00000000f0000000 x15: 0000000000000048
[ 4.208976] x14: 0000000000000048 x13: 0000000000000000 x12: 0000000000000001
[ 4.216179] x11: ffffffc08151a240 x10: 0000000000003ea1 x9 : ffffffc08046ab68
[ 4.223381] x8 : ffffffc083cabac0 x7 : ffffffc081df3718 x6 : 0000000000029fc8
[ 4.230583] x5 : ffffffc0817ee6d8 x4 : 0000000000000bc0 x3 : 0000000000000000
[ 4.237784] x2 : 0000000000000000 x1 : 00000000001fffff x0 : 0000000000000000
[ 4.244986] Call trace:
[ 4.247463] udma_start.isra.0+0x34/0x238
[ 4.251509] udma_check_tx_completion+0xd0/0xdc
[ 4.256076] process_one_work+0x244/0x3fc
[ 4.260129] process_scheduled_works+0x6c/0x74
[ 4.264610] worker_thread+0x150/0x1dc
[ 4.268398] kthread+0xd8/0xe8
[ 4.271492] ret_from_fork+0x10/0x20
[ 4.275107] irq event stamp: 220
[ 4.278363] hardirqs last enabled at (219): [<ffffffc080a27c7c>] _raw_spin_unlock_irq+0x38/0x50
[ 4.287183] hardirqs last disabled at (220): [<ffffffc080a1c154>] el1_dbg+0x24/0x50
[ 4.294879] softirqs last enabled at (182): [<ffffffc080037e68>] handle_softirqs+0x1c0/0x3cc
[ 4.303437] softirqs last disabled at (177): [<ffffffc080010170>] __do_softirq+0x1c/0x28
[ 4.311559] ---[ end trace 0000000000000000 ]---
This commit adds the missing locking.
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Analysis
by VulDB Data Team • 02/02/2026
The vulnerability identified as CVE-2025-38005 affects the Linux kernel's DMA engine implementation, specifically within the Texas Instruments K3 UDMA driver. This issue manifests as a missing lock in the k3-udma.c file which becomes apparent when the kernel's lock validator is enabled. The problem occurs during the execution of the udma_start function, which is part of the DMA transaction processing workflow. The kernel's lock validator detects an inconsistent locking pattern that could potentially lead to race conditions or data corruption in concurrent DMA operations.
The technical flaw resides in the absence of proper synchronization mechanisms within the UDMA driver's implementation. When the workqueue handler udma_check_tx_completion executes, it calls udma_start which attempts to access shared data structures without appropriate locking. This situation creates a potential race condition where multiple threads or processes might simultaneously access or modify the same DMA descriptor or channel state, leading to unpredictable behavior. The kernel warning message indicates that the issue originates from drivers/dma/ti/../virt-dma.h at line 169, specifically in the udma_start.isra.0 function, which is part of the virtual DMA subsystem that manages DMA transactions.
The operational impact of this vulnerability could be significant in systems relying on high-performance DMA operations, particularly in embedded systems or industrial applications using Texas Instruments K3 SoCs. When the lock validator is enabled, which is common in development environments or production systems with enhanced debugging capabilities, the kernel will generate warnings that may indicate potential data corruption or system instability. In production environments, this could lead to intermittent DMA transaction failures, corrupted data transfers, or even system crashes under high concurrency loads. The vulnerability is particularly concerning because DMA operations are fundamental to high-speed data transfer between hardware devices and memory, making this a critical issue for system reliability.
The mitigation for this vulnerability involves applying the patch that introduces the missing locking mechanism in the k3-udma.c driver. This fix ensures that all shared resources accessed by the DMA engine are properly protected using appropriate locking primitives such as spinlocks or mutexes. The solution aligns with common security practices for kernel development and follows the principles outlined in the Common Weakness Enumeration (CWE) category CWE-362, which addresses race conditions in concurrent programming. From an ATT&CK framework perspective, this vulnerability could be categorized under privilege escalation or denial of service techniques if exploited, as it affects the kernel's ability to properly manage DMA resources. The fix should be applied through standard kernel update procedures, with particular attention to systems where DMA operations are critical for system operation. Organizations should prioritize this patch, especially those using embedded systems or industrial control equipment that rely on the K3 UDMA driver for high-speed data transfer operations.