CVE-2022-50636

high

Published 2023-11-07 · Modified 2023-11-07

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CVSS v3

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CVSS v4 NEW

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not yet in upstream

VIR risk

8.0

Description

In the Linux kernel, the following vulnerability has been resolved: PCI: Fix pci_device_is_present() for VFs by checking PF pci_device_is_present() previously didn't work for VFs because it reads the Vendor and Device ID, which are 0xffff for VFs, which looks like they aren't present. Check the PF instead. Wei Gong reported that if virtio I/O is in progress when the driver is unbound or "0" is written to /sys/.../sriov_numvfs, the virtio I/O operation hangs, which may result in output like this: task:bash state:D stack: 0 pid: 1773 ppid: 1241 flags:0x00004002 Call Trace: schedule+0x4f/0xc0 blk_mq_freeze_queue_wait+0x69/0xa0 blk_mq_freeze_queue+0x1b/0x20 blk_cleanup_queue+0x3d/0xd0 virtblk_remove+0x3c/0xb0 [virtio_blk] virtio_dev_remove+0x4b/0x80 ... device_unregister+0x1b/0x60 unregister_virtio_device+0x18/0x30 virtio_pci_remove+0x41/0x80 pci_device_remove+0x3e/0xb0 This happened because pci_device_is_present(VF) returned "false" in virtio_pci_remove(), so it called virtio_break_device(). The broken vq meant that vring_interrupt() skipped the vq.callback() that would have completed the virtio I/O operation via virtblk_done(). [bhelgaas: commit log, simplify to always use pci_physfn(), add stable tag]

Predictions

Exploit likelihood

20%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

Mitigation details

Source: Debian Security Tracker · View original ↗ · DFSG

CVE-2022-50636 NameCVE-2022-50636 DescriptionIn the Linux kernel, the following vulnerability has been resolved: PCI: Fix pci_device_is_present() for VFs by checking PF pci_device_is_present() previously didn't work for VFs because it reads the Vendor and Device ID, which are 0xffff for VFs, which looks like they aren't present. Check the PF instead. Wei Gong reported that if virtio I/O is in…

CVE-2022-50636

Name	CVE-2022-50636
Description	In the Linux kernel, the following vulnerability has been resolved: PCI: Fix pci_device_is_present() for VFs by checking PF pci_device_is_present() previously didn't work for VFs because it reads the Vendor and Device ID, which are 0xffff for VFs, which looks like they aren't present. Check the PF instead. Wei Gong reported that if virtio I/O is in progress when the driver is unbound or "0" is written to /sys/.../sriov_numvfs, the virtio I/O operation hangs, which may result in output like this: task:bash state:D stack: 0 pid: 1773 ppid: 1241 flags:0x00004002 Call Trace: schedule+0x4f/0xc0 blk_mq_freeze_queue_wait+0x69/0xa0 blk_mq_freeze_queue+0x1b/0x20 blk_cleanup_queue+0x3d/0xd0 virtblk_remove+0x3c/0xb0 [virtio_blk] virtio_dev_remove+0x4b/0x80 ... device_unregister+0x1b/0x60 unregister_virtio_device+0x18/0x30 virtio_pci_remove+0x41/0x80 pci_device_remove+0x3e/0xb0 This happened because pci_device_is_present(VF) returned "false" in virtio_pci_remove(), so it called virtio_break_device(). The broken vq meant that vring_interrupt() skipped the vq.callback() that would have completed the virtio I/O operation via virtblk_done(). [bhelgaas: commit log, simplify to always use pci_physfn(), add stable tag]
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bullseye	5.10.223-1	fixed
	bullseye (security)	5.10.257-1	fixed
	bookworm	6.1.170-3	fixed
	bookworm (security)	6.1.172-1	fixed
	trixie	6.12.86-1	fixed
	trixie (security)	6.12.90-1	fixed
	forky	7.0.9-1	fixed
	sid	7.0.10-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
linux	source	bullseye	5.10.178-1
linux	source	(unstable)	6.1.4-1

Notes

https://git.kernel.org/linus/98b04dd0b4577894520493d96bc4623387767445 (6.2-rc1)

Home - Debian Security - Source (Git)

Apply commands

text fix

Notes

https://git.kernel.org/linus/98b04dd0b4577894520493d96bc4623387767445 (6.2-rc1)

OS impact

SUSE Affected 1 release

Version	Status	Fixed in
—	Affected	—

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`6.1.4-1`
sid	Fixed	`6.1.4-1`
forky	Fixed	`6.1.4-1`
bullseye	Fixed	`5.10.178-1`
bookworm	Fixed	`6.1.4-1`

Red Hat Fixed 1 release

Version	Status	Fixed in
9	Fixed	—

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.