CVE-2021-47112

x86/kvm: Teardown PV features on boot CPU as well

7.8 HighFix available

In the Linux kernel, the following vulnerability has been resolved:

x86/kvm: Teardown PV features on boot CPU as well

Various PV features (Async PF, PV EOI, steal time) work through memory shared with hypervisor and when we restore from hibernation we must properly teardown all these features to make sure hypervisor doesn't write to stale locations after we jump to the previously hibernated kernel (which can try to place anything there). For secondary CPUs the job is already done by kvm_cpu_down_prepare(), register syscore ops to do the same for boot CPU.

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.25%Up 0.2 points since Mar 16, 2024

What each source reports

CVE List Score used 7.8

x86/kvm: Teardown PV features on boot CPU as well

In the Linux kernel, the following vulnerability has been resolved:

x86/kvm: Teardown PV features on boot CPU as well

Record: CVE-2021-47112
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

EUVDEUVD-2021-33760 7.8

In the Linux kernel, the following vulnerability has been resolved:

x86/kvm: Teardown PV features on boot CPU as well

Record: EUVD-2021-33760
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

GitHub AdvisoriesGHSA-fq4q-x842-fmrh 5.5

In the Linux kernel, the following vulnerability has been resolved: x86/kvm: Teardown PV...

In the Linux kernel, the following vulnerability has been resolved:

x86/kvm: Teardown PV features on boot CPU as well

Record: GHSA-fq4q-x842-fmrh
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

NVD 7.8

In the Linux kernel, the following vulnerability has been resolved:

x86/kvm: Teardown PV features on boot CPU as well

Record: CVE-2021-47112
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSV 5.5

In the Linux kernel, the following vulnerability has been resolved:

x86/kvm: Teardown PV features on boot CPU as well

Record: CVE-2021-47112
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2021-47112 5.5

In the Linux kernel, the following vulnerability has been resolved: x86/kvm: Teardown PV features on boot CPU as well Various PV features (Async PF, PV EOI, steal time) work through memory shared with hypervisor and when we restore from hibernation we must properly teardown all these features to make sure hypervisor doesn't write to stale locations after we jump to the previously hibernated kernel (which can try to place anything there). For secondary CPUs the job is already done by kvm_cpu_down_prepare(), register syscore ops to do the same for boot CPU.

Record: DEBIAN-CVE-2021-47112
CVSS 3.1: 5.5 MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

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OSVOESA-2024-1392 7.8

kernel security update

The Linux Kernel, the operating system core itself.

Security Fix(es):

In the Linux kernel, the following vulnerability has been resolved:

media: dvbdev: Fix memory leak in dvb_media_device_free()

dvb_media_device_free() is leaking memory. Free dvbdev->adapter->conn before setting it to NULL, as documented in include/media/media-device.h: "The media_entity instance itself must be freed explicitly by the driver if required."(CVE-2020-36777)

In the Linux kernel, the following vulnerability has been resolved:

i2c: sprd: fix reference leak when pm_runtime_get_sync fails

The PM reference count is not expected to be incremented on return in sprd_i2c_master_xfer() and sprd_i2c_remove().

However, pm_runtime_get_sync will increment the PM reference count even failed. Forgetting to putting operation will result in a reference leak here.

Replace it with pm_runtime_resume_and_get to keep usage counter balanced.(CVE-2020-36780)

In the Linux kernel, the following vulnerability has been resolved:

i2c: cadence: fix reference leak when pm_runtime_get_sync fails

The PM reference count is not expected to be incremented on return in functions cdns_i2c_master_xfer and cdns_reg_slave.

However, pm_runtime_get_sync will increment pm usage counter even failed. Forgetting to putting operation will result in a reference leak here.

Replace it with pm_runtime_resume_and_get to keep usage counter balanced.(CVE-2020-36784)

In the Linux kernel, the following vulnerability has been resolved:

net: hso: fix null-ptr-deref during tty device unregistration

Multiple ttys try to claim the same the minor number causing a double unregistration of the same device. The first unregistration succeeds but the next one results in a null-ptr-deref.

The get_free_serial_index() function returns an available minor number but doesn't assign it immediately. The assignment is done by the caller later. But before this assignment, calls to get_free_serial_index() would return the same minor number.

Fix this by modifying get_free_serial_index to assign the minor number immediately after one is found to be and rename it to obtain_minor() to better reflect what it does. Similary, rename set_serial_by_index() to release_minor() and modify it to free up the minor number of the given hso_serial. Every obtain_minor() should have corresponding release_minor() call.(CVE-2021-46904)

In the Linux kernel, the following vulnerability has been resolved:

NFC: st21nfca: Fix memory leak in device probe and remove

'phy->pending_skb' is alloced when device probe, but forgot to free in the error handling path and remove path, this cause memory leak as follows:

unreferenced object 0xffff88800bc06800 (size 512): comm "8", pid 11775, jiffies 4295159829 (age 9.032s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000d66c09ce>] __kmalloc_node_track_caller+0x1ed/0x450 [<00000000c93382b3>] kmalloc_reserve+0x37/0xd0 [<000000005fea522c>] __alloc_skb+0x124/0x380 [<0000000019f29f9a>] st21nfca_hci_i2c_probe+0x170/0x8f2

Fix it by freeing 'pending_skb' in error and remove.(CVE-2021-46924)

In the Linux kernel, the following vulnerability has been resolved:

ALSA: hda: intel-sdw-acpi: harden detection of controller

The existing code currently sets a pointer to an ACPI handle before checking that it's actually a SoundWire controller. This can lead to issues where the graph walk continues and eventually fails, but the pointer was set already.

This patch changes the logic so that the information provided to the caller is set when a controller is found.(CVE-2021-46926)

In the Linux kernel, the following vulnerability has been resolved:

parisc: Clear stale IIR value on instruction access rights…

Record: OESA-2024-1392
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVOESA-2024-1393 7.8