CVE-2026-93194 in Linux
Summary
by MITRE • 09/18/2026
In the Linux kernel, the following vulnerability has been resolved:
drm/rockchip: dw_dp: Release core resources
Core resources such as the DisplayPort AUX channel get initialized and registered during dw_dp_bind(), but are never unregistered, which may lead to memory leaks and/or use-after-free:
[ 224.661371] BUG: KASAN: slab-use-after-free in device_is_dependent+0xe0/0x2b0
[ 224.662015] Read of size 8 at addr ffff00011aee8550 by task modprobe/658
[ 224.662612]
[ 224.662752] CPU: 7 UID: 0 PID: 658 Comm: modprobe Not tainted 7.0.0-rc2-next-20260305 #14 PREEMPT
[ 224.662759] Hardware name: Radxa ROCK 5B (DT)
[ 224.662762] Call trace:
[ 224.662764] show_stack+0x20/0x38 (C)
[ 224.662772] dump_stack_lvl+0x6c/0x98
[ 224.662777] print_report+0x160/0x4b8
[ 224.662783] kasan_report+0xb4/0xe0
[ 224.662790] __asan_report_load8_noabort+0x20/0x30
[ 224.662796] device_is_dependent+0xe0/0x2b0
[ 224.662802] device_is_dependent+0x108/0x2b0
[ 224.662808] device_link_add+0x1f8/0x10b0
[ 224.662813] devm_of_phy_get_by_index+0x120/0x200
[ 224.662819] dw_dp_bind+0x34c/0xb10 [dw_dp]
[ 224.662830] dw_dp_rockchip_bind+0x194/0x250 [rockchipdrm]
[ 224.662864] component_bind_all+0x3a8/0x720
[ 224.662869] rockchip_drm_bind+0x120/0x390 [rockchipdrm]
[ 224.662899] try_to_bring_up_aggregate_device+0x76c/0x838
[ 224.662904] component_master_add_with_match+0x1f4/0x230
[ 224.662909] rockchip_drm_platform_probe+0x420/0x538 [rockchipdrm]
[ 224.662939] platform_probe+0xe8/0x168
[ 224.662945] really_probe+0x340/0x828
[ 224.662950] __driver_probe_device+0x2e0/0x350
[ 224.662954] driver_probe_device+0x80/0x140
[ 224.662959] __driver_attach+0x398/0x460
[ 224.662964] bus_for_each_dev+0xe0/0x198
[ 224.662968] driver_attach+0x50/0x68
[ 224.662972] bus_add_driver+0x2a0/0x4c0
[ 224.662977] driver_register+0x294/0x360
[ 224.662982] __platform_driver_register+0x7c/0x98
[ 224.662987] rockchip_drm_init+0xc4/0xff8 [rockchipdrm]
Since a previous commit exported dw_dp_unbind() function in DW DP core library to take care of the necessary cleanup, use this in the component's unbind() callback, as well as in its bind() error path.
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Analysis
by VulDB Data Team • 09/18/2026
The Linux kernel driver for Rockchip DisplayPort interfaces contains a critical resource management flaw within the dw_dp subsystem that results in improper handling of core resources during device initialization and teardown sequences. Specifically, when the dw_dp_bind function is invoked to initialize the hardware, it registers various components including the DisplayPort AUX channel which facilitates communication between the host and connected display devices. However, the corresponding cleanup routine was not consistently executed upon driver unbinding or during error paths in the binding process. This asymmetry in resource allocation and deallocation creates a scenario where allocated kernel memory structures remain referenced after they should have been released, leading to potential stability issues within the operating system core.
The technical nature of this vulnerability is classified as an improper cleanup mechanism that leads to use-after-free conditions and memory leaks. The provided crash trace indicates a slab-use-after-free error detected by Kernel Address Sanitizer (KASAN), where the kernel attempted to read from a memory address associated with a device dependency structure after it had been freed or invalidated. This occurs because the dw_dp_unbind function, which contains the necessary logic to unregister and release these core resources, was not called in all exit paths of the driver lifecycle. Consequently, when the system attempts to access dependent devices during subsequent operations such as phy acquisition via devm_of_phy_get_by_index, it interacts with stale pointers or freed memory regions, triggering a kernel panic or undefined behavior that can destabilize the entire system.
From an operational impact perspective, this vulnerability primarily affects system stability and reliability rather than providing a direct avenue for remote code execution or privilege escalation in most standard configurations. The immediate consequence is a denial of service caused by kernel crashes when drivers are loaded, unloaded, or re-initialized on affected Rockchip hardware platforms such as the Radxa ROCK 5B. While local attackers with physical access might exploit repeated driver reloads to exhaust system resources through memory leaks, the primary risk remains the unpredictability and instability introduced into the graphics subsystem. This can lead to data corruption if critical display state is lost or cause cascading failures in other kernel components that rely on stable device dependencies.
To mitigate this vulnerability, it is essential to ensure that all allocated resources are properly released during both normal unbinding operations and error handling paths within the bind function. The resolution involves integrating the exported dw_dp_unbind routine into the component's unbind callback as well as its bind error path, ensuring symmetry between initialization and cleanup actions. This aligns with industry standards for secure coding practices in kernel development, specifically addressing CWE-401 which relates to missing release of memory after effective lifetime, and CWE-755 related to improper handling of unusual or exceptional conditions. Furthermore, this fix supports the integrity requirements outlined in ATT&CK techniques involving resource hijacking by preventing unauthorized persistence through leaked resources that could theoretically be manipulated if an attacker gains low-level access. System administrators should apply kernel updates containing these patches immediately to restore stability and prevent potential denial-of-service events on affected embedded systems utilizing Rockchip DisplayPort interfaces.