Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2026-45904 is a medium-severity Uncontrolled Recursion (CWE-674) vulnerability in Linux Linux Kernel. Its CVSS base score is 5.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-32370
Vulnerability Data
In the Linux kernel, the following vulnerability has been resolved: powerpc/eeh: fix recursive pci_lock_rescan_remove locking in EEH event handling The recent commit 1010b4c012b0 ("powerpc/eeh: Make EEH driver device hotplug safe") restructured the EEH driver to improve synchronization with the PCI…
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hotplug layer. However, it inadvertently moved pci_lock_rescan_remove() outside its intended scope in eeh_handle_normal_event(), leading to broken PCI error reporting and improper EEH event triggering. Specifically, eeh_handle_normal_event() acquired pci_lock_rescan_remove() before calling eeh_pe_bus_get(), but eeh_pe_bus_get() itself attempts to acquire the same lock internally, causing nested locking and disrupting normal EEH event handling paths. This patch adds a boolean parameter do_lock to _eeh_pe_bus_get(), with two public wrappers: eeh_pe_bus_get() with locking enabled. eeh_pe_bus_get_nolock() that skips locking. Callers that already hold pci_lock_rescan_remove() now use eeh_pe_bus_get_nolock() to avoid recursive lock acquisition. Additionally, pci_lock_rescan_remove() calls are restored to the correct position—after eeh_pe_bus_get() and immediately before iterating affected PEs and devices. This ensures EEH-triggered PCI removes occur under proper bus rescan locking without recursive lock contention. The eeh_pe_loc_get() function has been split into two functions: eeh_pe_loc_get(struct eeh_pe *pe) which retrieves the loc for given PE. eeh_pe_loc_get_bus(struct pci_bus *bus) which retrieves the location code for given bus. This resolves lockdep warnings such as: <snip> [ 84.964298] [ T928] ============================================ [ 84.964304] [ T928] WARNING: possible recursive locking detected [ 84.964311] [ T928] 6.18.0-rc3 #51 Not tainted [ 84.964315] [ T928] -------------------------------------------- [ 84.964320] [ T928] eehd/928 is trying to acquire lock: [ 84.964324] [ T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40 [ 84.964342] [ T928] but task is already holding lock: [ 84.964347] [ T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40 [ 84.964357] [ T928] other info that might help us debug this: [ 84.964363] [ T928] Possible unsafe locking scenario: [ 84.964367] [ T928] CPU0 [ 84.964370] [ T928] ---- [ 84.964373] [ T928] lock(pci_rescan_remove_lock); [ 84.964378] [ T928] lock(pci_rescan_remove_lock); [ 84.964383] [ T928] *** DEADLOCK *** [ 84.964388] [ T928] May be due to missing lock nesting notation [ 84.964393] [ T928] 1 lock held by eehd/928: [ 84.964397] [ T928] #0: c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40 [ 84.964408] [ T928] stack backtrace: [ 84.964414] [ T928] CPU: 2 UID: 0 PID: 928 Comm: eehd Not tainted 6.18.0-rc3 #51 VOLUNTARY [ 84.964417] [ T928] Hardware name: IBM,9080-HEX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_022) hv:phyp pSeries [ 84.964419] [ T928] Call Trace: [ 84.964420] [ T928] [c0000011a7157990] [c000000001705de4] dump_stack_lvl+0xc8/0x130 (unreliable) [ 84.964424] [ T928] [c0000011a71579d0] [c0000000002f66e0] print_deadlock_bug+0x430/0x440 [ 84.964428] [ T928] [c0000011a7157a70] [c0000000002fd0c0] __lock_acquire+0x1530/0x2d80 [ 84.964431] [ T928] [c0000011a7157ba0] [c0000000002fea54] lock_acquire+0x144/0x410 [ 84.964433] [ T928] [c0000011a7157cb0] [c0000011a7157cb0] __mutex_lock+0xf4/0x1050 [ 84.964436] [ T928] [c0000011a7157e00] [c000000000de21d8] pci_lock_rescan_remove+0x28/0x40 [ 84.964439] [ T928] [c0000011a7157e20] [c00000000004ed98] eeh_pe_bus_get+0x48/0xc0 [ 84.964442] [ T928] [c0000011a7157e50] [c00000 ---truncated---
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Input validation can reject or constrain data that would otherwise drive unbounded recursive calls.
DoS protection mechanisms limit the resource-exhaustion impact of uncontrolled recursion without eliminating the flaw.
System monitoring can observe anomalous resource consumption that signals runaway recursion after it begins.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly prevent coding errors such as missing recursion limits or termination conditions.
Runtime monitoring of compute resources can detect excessive consumption caused by uncontrolled recursion.
Vulnerability identification processes can discover and record uncontrolled recursion flaws before deployment.
Capacity monitoring and resource provisioning can absorb or limit the impact of runaway recursion.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect excessive recursion via static analysis or fuzzing.
Secure development life cycle requires controls that prevent uncontrolled recursion through design and code review.
Application security requirements can mandate recursion limits or stack-depth checks.
Secure system architecture principles include resource-management and input-validation rules that limit recursion.
Secure coding standards directly prohibit or constrain recursive constructs that could exhaust stack or memory.
Capacity management includes monitoring and limits that mitigate resource exhaustion from runaway recursion.