CVE-2025-40219
PCI/IOV: Fix race between SR-IOV enable/disable and hotplug
Description
In the Linux kernel, the following vulnerability has been resolved: PCI/IOV: Fix race between SR-IOV enable/disable and hotplug Commit 05703271c3cd ("PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV") tried to fix a race between the VF removal inside sriov_del_vfs() and concurrent hot unplug by taking the PCI rescan/remove lock in sriov_del_vfs(). Similarly the PCI rescan/remove lock was also taken in sriov_add_vfs() to protect addition of VFs. This approach however causes deadlock on trying to remove PFs with SR-IOV enabled because PFs disable SR-IOV during removal and this removal happens under the PCI rescan/remove lock. So the original fix had to be reverted. Instead of taking the PCI rescan/remove lock in sriov_add_vfs() and sriov_del_vfs(), fix the race that occurs with SR-IOV enable and disable vs hotplug higher up in the callchain by taking the lock in sriov_numvfs_store() before calling into the driver's sriov_configure() callback.
INFO
Published Date :
Dec. 4, 2025, 3:15 p.m.
Last Modified :
April 15, 2026, 12:35 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Apply the kernel patch to add missing PCI rescan-remove locks.
- Ensure synchronization for SR-IOV VFs addition and removal.
- Serialize PCI device and bus additions using the lock.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-40219.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-40219 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-40219
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-40219 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-40219 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 03, 2026
Action Type Old Value New Value Changed Description In the Linux kernel, the following vulnerability has been resolved: PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV Before disabling SR-IOV via config space accesses to the parent PF, sriov_disable() first removes the PCI devices representing the VFs. Since commit 9d16947b7583 ("PCI: Add global pci_lock_rescan_remove()") such removal operations are serialized against concurrent remove and rescan using the pci_rescan_remove_lock. No such locking was ever added in sriov_disable() however. In particular when commit 18f9e9d150fc ("PCI/IOV: Factor out sriov_add_vfs()") factored out the PCI device removal into sriov_del_vfs() there was still no locking around the pci_iov_remove_virtfn() calls. On s390 the lack of serialization in sriov_disable() may cause double remove and list corruption with the below (amended) trace being observed: PSW: 0704c00180000000 0000000c914e4b38 (klist_put+56) GPRS: 000003800313fb48 0000000000000000 0000000100000001 0000000000000001 00000000f9b520a8 0000000000000000 0000000000002fbd 00000000f4cc9480 0000000000000001 0000000000000000 0000000000000000 0000000180692828 00000000818e8000 000003800313fe2c 000003800313fb20 000003800313fad8 #0 [3800313fb20] device_del at c9158ad5c #1 [3800313fb88] pci_remove_bus_device at c915105ba #2 [3800313fbd0] pci_iov_remove_virtfn at c9152f198 #3 [3800313fc28] zpci_iov_remove_virtfn at c90fb67c0 #4 [3800313fc60] zpci_bus_remove_device at c90fb6104 #5 [3800313fca0] __zpci_event_availability at c90fb3dca #6 [3800313fd08] chsc_process_sei_nt0 at c918fe4a2 #7 [3800313fd60] crw_collect_info at c91905822 #8 [3800313fe10] kthread at c90feb390 #9 [3800313fe68] __ret_from_fork at c90f6aa64 #10 [3800313fe98] ret_from_fork at c9194f3f2. This is because in addition to sriov_disable() removing the VFs, the platform also generates hot-unplug events for the VFs. This being the reverse operation to the hotplug events generated by sriov_enable() and handled via pdev->no_vf_scan. And while the event processing takes pci_rescan_remove_lock and checks whether the struct pci_dev still exists, the lack of synchronization makes this checking racy. Other races may also be possible of course though given that this lack of locking persisted so long observable races seem very rare. Even on s390 the list corruption was only observed with certain devices since the platform events are only triggered by config accesses after the removal, so as long as the removal finished synchronously they would not race. Either way the locking is missing so fix this by adding it to the sriov_del_vfs() helper. Just like PCI rescan-remove, locking is also missing in sriov_add_vfs() including for the error case where pci_stop_and_remove_bus_device() is called without the PCI rescan-remove lock being held. Even in the non-error case, adding new PCI devices and buses should be serialized via the PCI rescan-remove lock. Add the necessary locking. In the Linux kernel, the following vulnerability has been resolved: PCI/IOV: Fix race between SR-IOV enable/disable and hotplug Commit 05703271c3cd ("PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV") tried to fix a race between the VF removal inside sriov_del_vfs() and concurrent hot unplug by taking the PCI rescan/remove lock in sriov_del_vfs(). Similarly the PCI rescan/remove lock was also taken in sriov_add_vfs() to protect addition of VFs. This approach however causes deadlock on trying to remove PFs with SR-IOV enabled because PFs disable SR-IOV during removal and this removal happens under the PCI rescan/remove lock. So the original fix had to be reverted. Instead of taking the PCI rescan/remove lock in sriov_add_vfs() and sriov_del_vfs(), fix the race that occurs with SR-IOV enable and disable vs hotplug higher up in the callchain by taking the lock in sriov_numvfs_store() before calling into the driver's sriov_configure() callback. Added Reference https://git.kernel.org/stable/c/1047ca2d816994f31e1475e63e0c0b7825599747 Added Reference https://git.kernel.org/stable/c/3cddde484471c602bea04e6f384819d336a1ff84 Added Reference https://git.kernel.org/stable/c/7c37920c96b85ef4255a7acc795e99e63dd38d59 Added Reference https://git.kernel.org/stable/c/97c18f074ff1c12d016a0753072a3afdfa0b9611 Added Reference https://git.kernel.org/stable/c/a5338e365c4559d7b4d7356116b0eb95b12e08d5 Added Reference https://git.kernel.org/stable/c/bea1d373098b22d7142da48750ce5526096425bc Added Reference https://git.kernel.org/stable/c/d7673ac466eca37ec3e6b7cc9ccdb06de3304e9b Added Reference https://git.kernel.org/stable/c/f3015627b6e9ddf85cfeaf42405b3c194dde2c36 Removed Reference https://git.kernel.org/stable/c/05703271c3cdcc0f2a8cf6ebdc45892b8ca83520 Removed Reference https://git.kernel.org/stable/c/1e8a80290f964bdbad225221c8a1594c7e01c8fd Removed Reference https://git.kernel.org/stable/c/36039348bca77828bf06eae41b8f76e38cd15847 Removed Reference https://git.kernel.org/stable/c/53154cd40ccf285f1d1c24367824082061d155bd Removed Reference https://git.kernel.org/stable/c/5c1cd7d405e94dc6cb320cc0cc092b74895b6ddf Removed Reference https://git.kernel.org/stable/c/a24219172456f035d886857e265ca24c85b167c8 Removed Reference https://git.kernel.org/stable/c/a645ca21de09e3137cbb224fa6c23cca873a1d01 Removed Reference https://git.kernel.org/stable/c/ee40e5db052d7c6f406fdb95ad639c894c74674c -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Dec. 04, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV Before disabling SR-IOV via config space accesses to the parent PF, sriov_disable() first removes the PCI devices representing the VFs. Since commit 9d16947b7583 ("PCI: Add global pci_lock_rescan_remove()") such removal operations are serialized against concurrent remove and rescan using the pci_rescan_remove_lock. No such locking was ever added in sriov_disable() however. In particular when commit 18f9e9d150fc ("PCI/IOV: Factor out sriov_add_vfs()") factored out the PCI device removal into sriov_del_vfs() there was still no locking around the pci_iov_remove_virtfn() calls. On s390 the lack of serialization in sriov_disable() may cause double remove and list corruption with the below (amended) trace being observed: PSW: 0704c00180000000 0000000c914e4b38 (klist_put+56) GPRS: 000003800313fb48 0000000000000000 0000000100000001 0000000000000001 00000000f9b520a8 0000000000000000 0000000000002fbd 00000000f4cc9480 0000000000000001 0000000000000000 0000000000000000 0000000180692828 00000000818e8000 000003800313fe2c 000003800313fb20 000003800313fad8 #0 [3800313fb20] device_del at c9158ad5c #1 [3800313fb88] pci_remove_bus_device at c915105ba #2 [3800313fbd0] pci_iov_remove_virtfn at c9152f198 #3 [3800313fc28] zpci_iov_remove_virtfn at c90fb67c0 #4 [3800313fc60] zpci_bus_remove_device at c90fb6104 #5 [3800313fca0] __zpci_event_availability at c90fb3dca #6 [3800313fd08] chsc_process_sei_nt0 at c918fe4a2 #7 [3800313fd60] crw_collect_info at c91905822 #8 [3800313fe10] kthread at c90feb390 #9 [3800313fe68] __ret_from_fork at c90f6aa64 #10 [3800313fe98] ret_from_fork at c9194f3f2. This is because in addition to sriov_disable() removing the VFs, the platform also generates hot-unplug events for the VFs. This being the reverse operation to the hotplug events generated by sriov_enable() and handled via pdev->no_vf_scan. And while the event processing takes pci_rescan_remove_lock and checks whether the struct pci_dev still exists, the lack of synchronization makes this checking racy. Other races may also be possible of course though given that this lack of locking persisted so long observable races seem very rare. Even on s390 the list corruption was only observed with certain devices since the platform events are only triggered by config accesses after the removal, so as long as the removal finished synchronously they would not race. Either way the locking is missing so fix this by adding it to the sriov_del_vfs() helper. Just like PCI rescan-remove, locking is also missing in sriov_add_vfs() including for the error case where pci_stop_and_remove_bus_device() is called without the PCI rescan-remove lock being held. Even in the non-error case, adding new PCI devices and buses should be serialized via the PCI rescan-remove lock. Add the necessary locking. Added Reference https://git.kernel.org/stable/c/05703271c3cdcc0f2a8cf6ebdc45892b8ca83520 Added Reference https://git.kernel.org/stable/c/1e8a80290f964bdbad225221c8a1594c7e01c8fd Added Reference https://git.kernel.org/stable/c/36039348bca77828bf06eae41b8f76e38cd15847 Added Reference https://git.kernel.org/stable/c/53154cd40ccf285f1d1c24367824082061d155bd Added Reference https://git.kernel.org/stable/c/5c1cd7d405e94dc6cb320cc0cc092b74895b6ddf Added Reference https://git.kernel.org/stable/c/a24219172456f035d886857e265ca24c85b167c8 Added Reference https://git.kernel.org/stable/c/a645ca21de09e3137cbb224fa6c23cca873a1d01 Added Reference https://git.kernel.org/stable/c/ee40e5db052d7c6f406fdb95ad639c894c74674c