CVE-2026-43147 - Vulnerability Details

- Revert "PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV"

Description

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 <NUM> > /sys/bus/pci/devices/<pf>/sriov_numvfs
$ echo 1 > /sys/bus/pci/devices/<pf>/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.

Published: 2026-05-06

Score: 5.5 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

The Linux kernel commit that was reverted re‑introduced a lock recursion in the PCI/IOV subsystem. When disabling SR‑IOV through the sysfs interface, the function sriov_del_vfs() attempts to acquire the pci_rescan_remove_lock while that lock is already held by pci_stop_and_remove_bus_device_locked. This causes a deadlock, which can stall the kernel and potentially lead to a system halt. The nature of the flaw is a lock ordering problem, corresponding to CWE-667 and the related deadlock CWE-833.

Affected Systems

All Linux kernel builds that contain the reverted commit, i.e. kernels prior to the application of a future fix that corrects the lock recursion. The vendor list indicates the generic Linux kernel, but no specific releases are enumerated. Administrators should review their kernel's patch history or source code to determine if the vulnerable logic is present.

Risk and Exploitability

The CVSS score of 5.5 indicates moderate severity. EPSS < 1% and no KEV listing suggest low exploitation risk. Requires privileged access to sysfs, inferred from normal permissions. Likely attack vector is local enable/disable of SR‑IOV.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`1e8a80290f964bdbad225221c8a1594c7e01c8fd`	affected	< f61cdd7e9b67bb8961b0a81bf294b78343e5db05
`a645ca21de09e3137cbb224fa6c23cca873a1d01`	affected	< 0de341b2365bad430aade0853fe09c2cbe468f59
`a24219172456f035d886857e265ca24c85b167c8`	affected	< 83651d37474c762920e345a3a0828f975ca4d732
`36039348bca77828bf06eae41b8f76e38cd15847`	affected	< 639265296fe6ee21b6f00e00ee2bab65f3b07252
`53154cd40ccf285f1d1c24367824082061d155bd`	affected	< d47f27e145f8bd13f3c230da5e3af29225b4a2f7
`05703271c3cdcc0f2a8cf6ebdc45892b8ca83520`	affected	< 40f67686a5002c0c322fac918406bbc8d9c2ec2f
`05703271c3cdcc0f2a8cf6ebdc45892b8ca83520`	affected	< 58677783c89681871077f50a7042b0c6380c4fd8
`05703271c3cdcc0f2a8cf6ebdc45892b8ca83520`	affected	< 2fa119c0e5e528453ebae9e70740e8d2d8c0ed5a
`5c1cd7d405e94dc6cb320cc0cc092b74895b6ddf`	affected	—
`ee40e5db052d7c6f406fdb95ad639c894c74674c`	affected	—
`5.10.246`	affected	< 5.10.252
`5.15.195`	affected	< 5.15.202
`6.1.157`	affected	< 6.1.165
`6.6.113`	affected	< 6.6.128
`6.12.54`	affected	< 6.12.75
`5.4.301`	affected	< 5.5
`6.17.4`	affected	< 6.18

Linux

affected

Version	Status	Constraints
`6.18`	affected	—
`0`	unaffected	< 6.18
`5.10.252`	unaffected	≤ 5.10.*
`5.15.202`	unaffected	≤ 5.15.*
`6.1.165`	unaffected	≤ 6.1.*
`6.6.128`	unaffected	≤ 6.6.*
`6.12.75`	unaffected	≤ 6.12.*
`6.18.16`	unaffected	≤ 6.18.*
`6.19.6`	unaffected	≤ 6.19.*
`7.0`	unaffected	≤ *

Configuration 1 [-]

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::

No data.

Vendor Product Confidence Versions

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`[1e8a80290f964bdbad225221c8a1594c7e01c8fd,f61cdd7e9b67bb8961b0a81bf294b78343e5db05)`	affected	code_commit	—
`[a645ca21de09e3137cbb224fa6c23cca873a1d01,0de341b2365bad430aade0853fe09c2cbe468f59)`	affected	code_commit	—
`[a24219172456f035d886857e265ca24c85b167c8,83651d37474c762920e345a3a0828f975ca4d732)`	affected	code_commit	—
`[36039348bca77828bf06eae41b8f76e38cd15847,639265296fe6ee21b6f00e00ee2bab65f3b07252)`	affected	code_commit	—
`[53154cd40ccf285f1d1c24367824082061d155bd,d47f27e145f8bd13f3c230da5e3af29225b4a2f7)`	affected	code_commit	—
`[05703271c3cdcc0f2a8cf6ebdc45892b8ca83520,40f67686a5002c0c322fac918406bbc8d9c2ec2f)`	affected	code_commit	—
`[05703271c3cdcc0f2a8cf6ebdc45892b8ca83520,58677783c89681871077f50a7042b0c6380c4fd8)`	affected	code_commit	—
`[05703271c3cdcc0f2a8cf6ebdc45892b8ca83520,2fa119c0e5e528453ebae9e70740e8d2d8c0ed5a)`	affected	code_commit	—
`5c1cd7d405e94dc6cb320cc0cc092b74895b6ddf`	affected	code_commit	—
`ee40e5db052d7c6f406fdb95ad639c894c74674c`	affected	code_commit	—

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`6.18`	affected	semver	—
`[0,6.18)`	unaffected	semver	—
`[5.10.252,5.10.*]`	unaffected	generic	—
`[5.15.202,5.15.*]`	unaffected	generic	—
`[6.1.165,6.1.*]`	unaffected	generic	—
`[6.6.128,6.6.*]`	unaffected	generic	—
`[6.12.75,6.12.*]`	unaffected	generic	—
`[6.18.16,6.18.*]`	unaffected	generic	—
`[6.19.6,6.19.*]`	unaffected	generic	—
`[7.0,*]`	unaffected	generic	—

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Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

Apply a Linux kernel update that incorporates the definitive fix for the pci_rescan_remove_lock recursion as it becomes available.
Restrict SR‑IOV configuration changes to trusted administrators and avoid rapid enable‑/‑disable cycles that can trigger the deadlock.
Enable kernel debug logging for the PCI subsystem, monitor /var/log/kern.log for deadlock warnings, and configure alerting to detect lock failures before they lead to a crash.

Generated by OpenCVE AI on May 13, 2026 at 22:13 UTC.

Tracking

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Advisories

Source	ID	Title
Debian DLA	DLA-4606-1	linux security update

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00012.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/0de341b2365bad430aade0853fe09c2cbe468f59
https://git.kernel.org/stable/c/2fa119c0e5e528453ebae9e70740e8d2d8c0ed5a
https://git.kernel.org/stable/c/40f67686a5002c0c322fac918406bbc8d9c2ec2f
https://git.kernel.org/stable/c/58677783c89681871077f50a7042b0c6380c4fd8
https://git.kernel.org/stable/c/639265296fe6ee21b6f00e00ee2bab65f3b07252
https://git.kernel.org/stable/c/83651d37474c762920e345a3a0828f975ca4d732
https://git.kernel.org/stable/c/d47f27e145f8bd13f3c230da5e3af29225b4a2f7
https://git.kernel.org/stable/c/f61cdd7e9b67bb8961b0a81bf294b78343e5db05
https://lore.kernel.org/linux-cve-announce/2026050627-CVE-2026-43147-4a3c@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2026-43147
https://www.cve.org/CVERecord?id=CVE-2026-43147

History

Wed, 13 May 2026 20:30:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-667

Thu, 07 May 2026 00:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-833
References		https://lore.kernel.org/linux-cve-announce/2026050627-CVE-2026-43147-4a3c@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2026-43147 https://www.cve.org/CVERecord?id=CVE-2026-43147
Metrics	threat_severity `None`	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Low`

Wed, 06 May 2026 12:15:00 +0000

Type	Values Removed	Values Added
Description		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 <NUM> > /sys/bus/pci/devices/<pf>/sriov_numvfs $ echo 1 > /sys/bus/pci/devices/<pf>/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.
Title		Revert "PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV"
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/0de341b2365bad430aade0853fe09c2cbe468f59 https://git.kernel.org/stable/c/2fa119c0e5e528453ebae9e70740e8d2d8c0ed5a https://git.kernel.org/stable/c/40f67686a5002c0c322fac918406bbc8d9c2ec2f https://git.kernel.org/stable/c/58677783c89681871077f50a7042b0c6380c4fd8 https://git.kernel.org/stable/c/639265296fe6ee21b6f00e00ee2bab65f3b07252 https://git.kernel.org/stable/c/83651d37474c762920e345a3a0828f975ca4d732 https://git.kernel.org/stable/c/d47f27e145f8bd13f3c230da5e3af29225b4a2f7 https://git.kernel.org/stable/c/f61cdd7e9b67bb8961b0a81bf294b78343e5db05

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-05-06T11:27:30.235Z

Updated: 2026-05-23T16:06:24.518Z

Reserved: 2026-05-01T14:12:55.989Z

Link: CVE-2026-43147

Vulnrichment

No data.

NVD

Status : Analyzed

Published: 2026-05-06T12:16:32.240

Modified: 2026-05-13T20:18:47.387

Link: CVE-2026-43147

Redhat

Severity : Low

Publid Date: 2026-05-06T00:00:00Z

Links: CVE-2026-43147 - Bugzilla

OpenCVE Enrichment

Updated: 2026-05-13T22:15:09Z

Weaknesses

Impact

Affected Systems

Risk and Exploitability

Tracking

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Subscriptions

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