Summary
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Replace Mutex...
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Replace Mutex with Spinlock for RLCG register access to avoid Priority Inversion in SRIOV
RLCG Register Access is a way for virtual functions to safely access GPU
registers in a virtualized environment., including TLB flushes and
register reads. When multiple threads or VFs try to access the same
registers simultaneously, it can lead to race conditions. By using the
RLCG interface, the driver can serialize access to the registers. This
means that only one thread can access the registers at a time,
preventing conflicts and ensuring that operations are performed
correctly. Additionally, when a low-priority task holds a mutex that a
high-priority task needs, ie., If a thread holding a spinlock tries to
acquire a mutex, it can lead to priority inversion. register access in
amdgpu_virt_rlcg_reg_rw especially in a fast code path is critical.
The call stack shows that the function amdgpu_virt_rlcg_reg_rw is being
called, which attempts to acquire the mutex. This function is invoked
from amdgpu_sriov_wreg, which in turn is called from
gmc_v11_0_flush_gpu_tlb.
The [ BUG: Invalid wait context ] indicates that a thread is trying to
acquire a mutex while it is in a context that does not allow it to sleep
(like holding a spinlock).
Fixes the below:
[ 253.013423] =============================
[ 253.013434] [ BUG: Invalid wait context ]
[ 253.013446] 6.12.0-amdstaging-drm-next-lol-050225 #14 Tainted: G U OE
[ 253.013464] -----------------------------
[ 253.013475] kworker/0:1/10 is trying to lock:
[ 253.013487] ffff9f30542e3cf8 (&adev->virt.rlcg_reg_lock){+.+.}-{3:3}, at: amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[ 253.013815] other info that might help us debug this:
[ 253.013827] context-{4:4}
[ 253.013835] 3 locks held by kworker/0:1/10:
[ 253.013847] #0: ffff9f3040050f58 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x3f5/0x680
[ 253.013877] #1: ffffb789c008be40 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: process_one_work+0x1d6/0x680
[ 253.013905] #2: ffff9f3054281838 (&adev->gmc.invalidate_lock){+.+.}-{2:2}, at: gmc_v11_0_flush_gpu_tlb+0x198/0x4f0 [amdgpu]
[ 253.014154] stack backtrace:
[ 253.014164] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Tainted: G U OE 6.12.0-amdstaging-drm-next-lol-050225 #14
[ 253.014189] Tainted: [U]=USER, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[ 253.014203] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/18/2024
[ 253.014224] Workqueue: events work_for_cpu_fn
[ 253.014241] Call Trace:
[ 253.014250]
[ 253.014260] dump_stack_lvl+0x9b/0xf0
[ 253.014275] dump_stack+0x10/0x20
[ 253.014287] __lock_acquire+0xa47/0x2810
[ 253.014303] ? srso_alias_return_thunk+0x5/0xfbef5
[ 253.014321] lock_acquire+0xd1/0x300
[ 253.014333] ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[ 253.014562] ? __lock_acquire+0xa6b/0x2810
[ 253.014578] __mutex_lock+0x85/0xe20
[ 253.014591] ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[ 253.014782] ? sched_clock_noinstr+0x9/0x10
[ 253.014795] ? srso_alias_return_thunk+0x5/0xfbef5
[ 253.014808] ? local_clock_noinstr+0xe/0xc0
[ 253.014822] ? amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[ 253.015012] ? srso_alias_return_thunk+0x5/0xfbef5
[ 253.015029] mutex_lock_nested+0x1b/0x30
[ 253.015044] ? mutex_lock_nested+0x1b/0x30
[ 253.015057] amdgpu_virt_rlcg_reg_rw+0xf6/0x330 [amdgpu]
[ 253.015249] amdgpu_sriov_wreg+0xc5/0xd0 [amdgpu]
[ 253.015435] gmc_v11_0_flush_gpu_tlb+0x44b/0x4f0 [amdgpu]
[ 253.015667] gfx_v11_0_hw_init+0x499/0x29c0 [amdgpu]
[ 253.015901] ? __pfx_smu_v13_0_update_pcie_parameters+0x10/0x10 [amdgpu]
[ 253.016159] ? srso_alias_return_thunk+0x5/0xfbef5
[ 253.016173] ? smu_hw_init+0x18d/0x300 [amdgpu]
[ 253.016403] amdgpu_device_init+0x29ad/0x36a0 [amdgpu]
[ 253.016614] amdgpu_driver_load_kms+0x1a/0xc0 [amdgpu]
[ 253.0170
---truncated---
Impact
Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing. Typical impact: TOCTOU exploits, data corruption, or privilege escalation.
CVE-2025-38104 has a CVSS score of 4.7 (Medium). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-38104? CVE-2025-38104 is a medium-severity race condition vulnerability. No fixed version is listed yet. Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing.
- How severe is CVE-2025-38104? CVE-2025-38104 has a CVSS score of 4.7 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Is there a fix for CVE-2025-38104? No fixed version is listed for CVE-2025-38104 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-38104 exploitable, and should I be worried? Whether CVE-2025-38104 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-38104 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.