CVE-2026-45904

Description

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 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---

Gravité et risque d'exploitation

CVE-2026-45904 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.16 %, ce qui la place devant 5.1 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.1.*, <f8b16d5764ee1e78c1ef333017ad383ffe76fcdc, <=6.12.*, a426e8a6ae161f51888585b065db0f8f93ab2e16, d42bbd8f30ac38b1ce54715bf08ec3dac18d6b25, 19d5036e7ad766cf212aebec23b9f1d7924a62bc, 59c6d3d81d42bf543c90597b4f38c53d6874c5a1, 6.17, 0, <f49faa4a64f8ac0e38983e606075b25dfcfc9ad4, <6.1.165, 7.0, 6.1.165, 6.12.75, <b85ee287bfe52c6b2d9b41758b5e0d08679d5b39, <87a1f93986aa1500b85aeff16b0b71c29ea116ea, <=5.10.*, <=6.6.*, 6.16.1, <=6.19.*, 5.15.190, f56e004b781719d8fdf6c9619b15caf2579bc1f2, 6.12.42, <5.10.252, <6.12.75, 1010b4c012b0d78dfb9d3132b49aa2ef024a07a7, 502f08831a9afb72dc98a56ae6504da43e93b250, <=6.18.*, 6.6.102, <89810e2d80281d42f855fac813786758ee16e323, <6.17, 6.6.128, 5.10.252, <6e6561231c6cfc32c5631aeecc0928ff2b14265c, 6.15.10, <6.16, 6.19.4, 5.10.241, <6.6.128, <=*, <=5.15.*, d2c60a8a387e9fcc28447ef36c03f8e49fd052a6, <788dd28fd49610d6047cbb15dbf1186afffdfbaf, 6.1.148, 5.15.202, 6.18.14, <5.15.202, <815a8d2feb5615ae7f0b5befd206af0b0160614c) est présent sur votre parc.
• Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
• À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
• Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

• https://git.kernel.org/stable/c/89810e2d80281d42f855fac813786758ee16e323
• https://git.kernel.org/stable/c/788dd28fd49610d6047cbb15dbf1186afffdfbaf
• https://git.kernel.org/stable/c/f49faa4a64f8ac0e38983e606075b25dfcfc9ad4
• https://git.kernel.org/stable/c/87a1f93986aa1500b85aeff16b0b71c29ea116ea
• https://git.kernel.org/stable/c/f8b16d5764ee1e78c1ef333017ad383ffe76fcdc
• https://git.kernel.org/stable/c/6e6561231c6cfc32c5631aeecc0928ff2b14265c
• https://git.kernel.org/stable/c/b85ee287bfe52c6b2d9b41758b5e0d08679d5b39
• https://git.kernel.org/stable/c/815a8d2feb5615ae7f0b5befd206af0b0160614c