In the Linux kernel, the following vulnerability has been resolved:
Revert "PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV"
This reverts commit 05703271c3cd ("PCI/IOV: Add PCI rescan-remove locking
when enabling/disabling SR-IOV"), which causes a deadlock by recursively
taking pci_rescan_remove_lock when sriov_del_vfs() is called as part of
pci_stop_and_remove_bus_device(). For example with the following sequence
of commands:
$ echo > /sys/bus/pci/devices//sriov_numvfs
$ echo 1 > /sys/bus/pci/devices//remove
A trimmed trace of the deadlock on a mlx5 device is as below:
zsh/5715 is trying to acquire lock:
000002597926ef50 (pci_rescan_remove_lock){+.+.}-{3:3}, at: sriov_disable+0x34/0x140
but task is already holding lock:
000002597926ef50 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_stop_and_remove_bus_device_locked+0x24/0x80
...
Call Trace:
[<00000259778c4f90>] dump_stack_lvl+0xc0/0x110
[<00000259779c844e>] print_deadlock_bug+0x31e/0x330
[<00000259779c1908>] __lock_acquire+0x16c8/0x32f0
[<00000259779bffac>] lock_acquire+0x14c/0x350
[<00000259789643a6>] __mutex_lock_common+0xe6/0x1520
[<000002597896413c>] mutex_lock_nested+0x3c/0x50
[<00000259784a07e4>] sriov_disable+0x34/0x140
[<00000258f7d6dd80>] mlx5_sriov_disable+0x50/0x80 [mlx5_core]
[<00000258f7d5745e>] remove_one+0x5e/0xf0 [mlx5_core]
[<00000259784857fc>] pci_device_remove+0x3c/0xa0
[<000002597851012e>] device_release_driver_internal+0x18e/0x280
[<000002597847ae22>] pci_stop_bus_device+0x82/0xa0
[<000002597847afce>] pci_stop_and_remove_bus_device_locked+0x5e/0x80
[<00000259784972c2>] remove_store+0x72/0x90
[<0000025977e6661a>] kernfs_fop_write_iter+0x15a/0x200
[<0000025977d7241c>] vfs_write+0x24c/0x300
[<0000025977d72696>] ksys_write+0x86/0x110
[<000002597895b61c>] __do_syscall+0x14c/0x400
[<000002597896e0ee>] system_call+0x6e/0x90
This alone is not a complete fix as it restores the issue the cited commit
tried to solve. A new fix will be provided as a follow on.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- <0.1% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-11). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it