CVE-2026-43147

CVE-2026-43147 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-667.

Key facts

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.

Frequently asked questions

What is CVE-2026-43147?
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.
How severe is CVE-2026-43147?
CVE-2026-43147 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-43147 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43147?
CVE-2026-43147 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-43147?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-43147 have an EU (EUVD) identifier?
Yes. CVE-2026-43147 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-27707.
When was CVE-2026-43147 published?
CVE-2026-43147 was published on 2026-05-06 and last updated on 2026-06-17.

References

Affected products (1)

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