CVE-2026-43147
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.
FAQ
CVE-2026-43147 has a CVSS score of N/A/10, rated as Unknown. Review the affected products list and apply vendor patches.
CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2026-43147 scores N/A/10 (Unknown). Scores 9.0–10.0 are Critical, 7.0–8.9 are High, 4.0–6.9 are Medium, and below 4.0 are Low.
The list of devices confirmed to be affected by CVE-2026-43147 is shown in the "Affected Devices" section above. Check your firmware version against the vendor security advisory and apply the latest patch.
Apply the latest firmware or software update from the vendor. Check the References section above for official advisories and patch notes. If no patch is available, consider disabling the affected feature or isolating the device from untrusted networks.