CVE-2025-68244
NoneCVSS
—
EPSS
0.2%
Published
Dec 16, 2025
CISA due date
—
Cloudanix analysis
A bug in the Linux graphics driver could cause certain older Intel-based computers to freeze or become unresponsive during graphics operations.
- Exploitation
- Local Privilege
- Attacker needs
- Local User
- Complexity
- Moderate
- Impact
- Denial Of Service
- Component
- OS kernel
- Class
- Race Condition
- Remediation
- Upgrade
- Effort
- Medium
- Patch risk
- Low
What it actually does
Potential circular locking dependency between reservation_ww_class_mutex (held during i915_vma_pin) and cpu_hotplug_lock (acquired via stop_machine in intel_ggtt_bind_vma) on Cherry View or Broxton+VTD configurations, which can trigger deadlock during GGTT pinning operations.
Why it matters to the business
May cause graphics subsystem hangs or kernel deadlocks on affected Intel hardware, leading to system instability, reduced availability for workloads using the i915 driver, and increased operational overhead for affected Linux deployments; prevalence in AlmaLinux 8 ecosystems amplifies patch urgency.
How an attack unfolds
An attacker with local access triggers VMA pinning to GGTT on vulnerable CHV/BXT hardware while VTD is enabled, causing the kernel to attempt acquiring cpu_hotplug_lock while already holding reservation_ww, resulting in lock inversion and potential denial of service via deadlock; no named threat actors or ransomware use reported.
How to fix it
Upgrade the Linux kernel to commit e988634d7aae7214818b9c86cd7ef9e78c84b02d or later; on AlmaLinux 8 apply the listed fixed package versions such as gcc-toolset-13-gcc 13.3.1-2.2.el8_10 and equivalent updates for all affected libasan/libtsan and related packages.
How to confirm the fix worked
Verify kernel version or package versions match the fixed releases; reproduce the original lockdep scenario and confirm absence of circular dependency warnings; run lockdep-enabled kernels and monitor for cpu_hotplug_lock / reservation_ww_class_mutex inversions.
Typical attack path
- Obtain local code execution or user privileges on affected system
- Invoke i915 graphics operations that call i915_vma_pin_ww on GGTT for CHV/BXT+VTD
- Trigger stop_machine path in intel_ggtt_bind_vma while holding reservation lock
- Induce lock inversion leading to deadlock or warning
How to detect it
Search kernel logs for the circular locking dependency warning involving cpu_hotplug_lock and reservation_ww_class_mutex during i915 module load or VMA pinning; inspect dmesg and journalctl for stop_machine calls under i915_vma_pin on affected hardware.
- WARNING: possible circular locking dependency detected
- cpu_hotplug_lock
- reservation_ww_class_mutex
- i915_vma_pin.constprop
- stop_machine+0x1c/0x50
What your security team should do
- Prioritize kernel and AlmaLinux package updates on all systems using i915 on CHV/BXT hardware within CISA timelines if applicable
- Enable lockdep and kernel debugging on test systems to validate no inversion occurs post-patch
- Monitor for i915-related stability issues and schedule hardware refreshes for legacy Cherry View/Broxton platforms
The record
In the Linux kernel, the following vulnerability has been resolved: drm/i915: Avoid lock inversion when pinning to GGTT on CHV/BXT+VTD On completion of i915_vma_pin_ww(), a synchronous variant of dma_fence_work_commit() is called. When pinning a VMA to GGTT address space on a Cherry View family processor, or on a Broxton generation SoC with VTD enabled, i.e., when stop_machine() is then called from intel_ggtt_bind_vma(), that can potentially lead to lock inversion among reservation_ww and cpu_hotplug locks. [86.861179] ====================================================== [86.861193] WARNING: possible circular locking dependency detected [86.861209] 6.15.0-rc5-CI_DRM_16515-gca0305cadc2d+ #1 Tainted: G U [86.861226] ------------------------------------------------------ [86.861238] i915_module_loa/1432 is trying to acquire lock: [86.861252] ffffffff83489090 (cpu_hotplug_lock){++++}-{0:0}, at: stop_machine+0x1c/0x50 [86.861290] but task is already holding lock: [86.861303] ffffc90002e0b4c8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.0+0x39/0x1d0 [i915] [86.862233] which lock already depends on the new lock. [86.862251] the existing dependency chain (in reverse order) is: [86.862265] -> #5 (reservation_ww_class_mutex){+.+.}-{3:3}: [86.862292] dma_resv_lockdep+0x19a/0x390 [86.862315] do_one_initcall+0x60/0x3f0 [86.862334] kernel_init_freeable+0x3cd/0x680 [86.862353] kernel_init+0x1b/0x200 [86.862369] ret_from_fork+0x47/0x70 [86.862383] ret_from_fork_asm+0x1a/0x30 [86.862399] -> #4 (reservation_ww_class_acquire){+.+.}-{0:0}: [86.862425] dma_resv_lockdep+0x178/0x390 [86.862440] do_one_initcall+0x60/0x3f0 [86.862454] kernel_init_freeable+0x3cd/0x680 [86.862470] kernel_init+0x1b/0x200 [86.862482] ret_from_fork+0x47/0x70 [86.862495] ret_from_fork_asm+0x1a/0x30 [86.862509] -> #3 (&mm->mmap_lock){++++}-{3:3}: [86.862531] down_read_killable+0x46/0x1e0 [86.862546] lock_mm_and_find_vma+0xa2/0x280 [86.862561] do_user_addr_fault+0x266/0x8e0 [86.862578] exc_page_fault+0x8a/0x2f0 [86.862593] asm_exc_page_fault+0x27/0x30 [86.862607] filldir64+0xeb/0x180 [86.862620] kernfs_fop_readdir+0x118/0x480 [86.862635] iterate_dir+0xcf/0x2b0 [86.862648] __x64_sys_getdents64+0x84/0x140 [86.862661] x64_sys_call+0x1058/0x2660 [86.862675] do_syscall_64+0x91/0xe90 [86.862689] entry_SYSCALL_64_after_hwframe+0x76/0x7e [86.862703] -> #2 (&root->kernfs_rwsem){++++}-{3:3}: [86.862725] down_write+0x3e/0xf0 [86.862738] kernfs_add_one+0x30/0x3c0 [86.862751] kernfs_create_dir_ns+0x53/0xb0 [86.862765] internal_create_group+0x134/0x4c0 [86.862779] sysfs_create_group+0x13/0x20 [86.862792] topology_add_dev+0x1d/0x30 [86.862806] cpuhp_invoke_callback+0x4b5/0x850 [86.862822] cpuhp_issue_call+0xbf/0x1f0 [86.862836] __cpuhp_setup_state_cpuslocked+0x111/0x320 [86.862852] __cpuhp_setup_state+0xb0/0x220 [86.862866] topology_sysfs_init+0x30/0x50 [86.862879] do_one_initcall+0x60/0x3f0 [86.862893] kernel_init_freeable+0x3cd/0x680 [86.862908] kernel_init+0x1b/0x200 [86.862921] ret_from_fork+0x47/0x70 [86.862934] ret_from_fork_asm+0x1a/0x30 [86.862947] -> #1 (cpuhp_state_mutex){+.+.}-{3:3}: [86.862969] __mutex_lock+0xaa/0xed0 [86.862982] mutex_lock_nested+0x1b/0x30 [86.862995] __cpuhp_setup_state_cpuslocked+0x67/0x320 [86.863012] __cpuhp_setup_state+0xb0/0x220 [86.863026] page_alloc_init_cpuhp+0x2d/0x60 [86.863041] mm_core_init+0x22/0x2d0 [86.863054] start_kernel+0x576/0xbd0 [86.863068] x86_64_start_reservations+0x18/0x30 [86.863084] x86_64_start_kernel+0xbf/0x110 [86.863098] common_startup_64+0x13e/0x141 [86.863114] -> #0 (cpu_hotplug_lock){++++}-{0:0}: [86.863135] __lock_acquire+0x16 ---truncated---
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| Linux | Kernel | 5.13.0 | 5.15.197 |
| Mageia:9 | kernel | 0 | 6.6.120-1.mga9 |
| Mageia:9 | kernel-linus | 0 | 6.6.120-1.mga9 |
| Mageia:9 | kmod-virtualbox | 0 | 7.1.14-14.mga9 |
| Mageia:9 | kmod-xtables-addons | 0 | 3.24-88.mga9 |
| SUSE:Linux Enterprise High Availability Extension 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_19 | 0 | 1-150600.13.3.1 |
| SUSE:Linux Enterprise Server 15 SP6-LTSS | kernel-64kb | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Server 15 SP6-LTSS | kernel-default | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Server 15 SP6-LTSS | kernel-default-base | 0 | 6.4.0-150600.23.84.1.150600.12.38.1 |
| SUSE:Linux Enterprise Server 15 SP6-LTSS | kernel-docs | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Server 15 SP6-LTSS | kernel-obs-build | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Server 15 SP6-LTSS | kernel-source | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Server 15 SP6-LTSS | kernel-syms | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Server 15 SP6-LTSS | kernel-zfcpdump | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Server for SAP Applications 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Server for SAP Applications 15 SP6 | kernel-default-base | 0 | 6.4.0-150600.23.84.1.150600.12.38.1 |
| SUSE:Linux Enterprise Server for SAP Applications 15 SP6 | kernel-docs | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Server for SAP Applications 15 SP6 | kernel-obs-build | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Server for SAP Applications 15 SP6 | kernel-source | 0 | 6.4.0-150600.23.84.1 |
| SUSE:Linux Enterprise Server for SAP Applications 15 SP6 | kernel-syms | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 15.6 | dtb-aarch64 | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 15.6 | kernel-64kb | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 15.6 | kernel-debug | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 15.6 | kernel-default | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 15.6 | kernel-default-base | 0 | 6.4.0-150600.23.84.1.150600.12.38.1 |
| openSUSE:Leap 15.6 | kernel-docs | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 15.6 | kernel-kvmsmall | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 15.6 | kernel-obs-build | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 15.6 | kernel-obs-qa | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 15.6 | kernel-source | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 15.6 | kernel-syms | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 15.6 | kernel-zfcpdump | 0 | 6.4.0-150600.23.84.1 |
| openSUSE:Leap 16.0 | dtb-aarch64 | 0 | 6.12.0-160000.9.1 |
| openSUSE:Leap 16.0 | kernel-64kb | 0 | 6.12.0-160000.9.1 |
| openSUSE:Leap 16.0 | kernel-azure | 0 | 6.12.0-160000.9.1 |
| openSUSE:Leap 16.0 | kernel-default | 0 | 6.12.0-160000.9.1 |
| openSUSE:Leap 16.0 | kernel-default-base | 0 | 6.12.0-160000.9.1.160000.2.6 |
| openSUSE:Leap 16.0 | kernel-docs | 0 | 6.12.0-160000.9.1 |
| openSUSE:Leap 16.0 | kernel-kvmsmall | 0 | 6.12.0-160000.9.1 |
| openSUSE:Leap 16.0 | kernel-obs-build | 0 | 6.12.0-160000.9.1 |
| openSUSE:Leap 16.0 | kernel-obs-qa | 0 | 6.12.0-160000.9.1 |
| openSUSE:Leap 16.0 | kernel-rt | 0 | 6.12.0-160000.9.1 |
| openSUSE:Leap 16.0 | kernel-source | 0 | 6.12.0-160000.9.1 |
| openSUSE:Leap 16.0 | kernel-syms | 0 | 6.12.0-160000.9.1 |
| openSUSE:Leap 16.0 | kernel-zfcpdump | 0 | 6.12.0-160000.9.1 |
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