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] <TASK>
[ 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---
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 17 Jul 2025 17:15:00 +0000


Sat, 19 Apr 2025 02:00:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Fri, 18 Apr 2025 07:15:00 +0000

Type Values Removed Values Added
Description 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] <TASK> [ 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---
Title drm/amdgpu: Replace Mutex with Spinlock for RLCG register access to avoid Priority Inversion in SRIOV
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-07-17T16:55:36.648Z

Reserved: 2025-04-16T04:51:23.985Z

Link: CVE-2025-38104

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-04-18T07:15:43.290

Modified: 2025-07-17T17:15:36.830

Link: CVE-2025-38104

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-04-18T00:00:00Z

Links: CVE-2025-38104 - Bugzilla

cve-icon OpenCVE Enrichment

No data.