Answer in brief
CVE-2025-21876 records a High severity (CVSS 8.8) vulnerability in iommu/vt-d: Fix suspicious RCU usage. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=d74169ceb0d2e32438946a2f1f9fc8c803304bd6 <4117c72938493a77ab53cc4b8284be8fb6ec8065 || >=d74169ceb0d2e32438946a2f1f9fc8c803304bd6 <c603ccbe91d189849e1439134598ec567088dcec || >=d74169ceb0d2e32438946a2f1f9fc8c803304bd6 <b150654f74bf0df8e6a7936d5ec51400d9ec06d8 | 4117c72938493a77ab53cc4b8284be8fb6ec8065, c603ccbe91d189849e1439134598ec567088dcec, b150654f74bf0df8e6a7936d5ec51400d9ec06d8 |
| Linux/Linuxgeneric | 6.10 | Not reported |
Published upstream
Mar 27, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix suspicious RCU usage Commit <d74169ceb0d2> ("iommu/vt-d: Allocate DMAR fault interrupts locally") moved the call to enable_drhd_fault_handling() to a code path that does not hold any lock while traversing the drhd list. Fix it by ensuring the dmar_global_lock lock is held when traversing the drhd list. Without this fix, the following warning is triggered: ============================= WARNING: suspicious RCU usage 6.14.0-rc3 #55 Not tainted ----------------------------- drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 2 locks held by cpuhp/1/23: #0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0 #1: ffffffff84a6a380 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0 stack backtrace: CPU: 1 UID: 0 PID: 23 Comm: cpuhp/1 Not tainted 6.14.0-rc3 #55 Call Trace: <TASK> dump_stack_lvl+0xb7/0xd0 lockdep_rcu_suspicious+0x159/0x1f0 ? __pfx_enable_drhd_fault_handling+0x10/0x10 enable_drhd_fault_handling+0x151/0x180 cpuhp_invoke_callback+0x1df/0x990 cpuhp_thread_fun+0x1ea/0x2c0 smpboot_thread_fn+0x1f5/0x2e0 ? __pfx_smpboot_thread_fn+0x10/0x10 kthread+0x12a/0x2d0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x4a/0x60 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Holding the lock in enable_drhd_fault_handling() triggers a lockdep splat about a possible deadlock between dmar_global_lock and cpu_hotplug_lock. This is avoided by not holding dmar_global_lock when calling iommu_device_register(), which initiates the device probe process.
Quoted source text, attributed separately from HOL analysis.