CVE-2021-47217

x86/hyperv: Fix NULL deref in set_hv_tscchange_cb() if Hyper-V setup fails

Severity Score

"-"

*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

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

x86/hyperv: Fix NULL deref in set_hv_tscchange_cb() if Hyper-V setup fails

Check for a valid hv_vp_index array prior to derefencing hv_vp_index when
setting Hyper-V's TSC change callback. If Hyper-V setup failed in
hyperv_init(), the kernel will still report that it's running under
Hyper-V, but will have silently disabled nearly all functionality.

BUG: kernel NULL pointer dereference, address: 0000000000000010
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] SMP
CPU: 4 PID: 1 Comm: swapper/0 Not tainted 5.15.0-rc2+ #75
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:set_hv_tscchange_cb+0x15/0xa0
Code: <8b> 04 82 8b 15 12 17 85 01 48 c1 e0 20 48 0d ee 00 01 00 f6 c6 08
...
Call Trace:
kvm_arch_init+0x17c/0x280
kvm_init+0x31/0x330
vmx_init+0xba/0x13a
do_one_initcall+0x41/0x1c0
kernel_init_freeable+0x1f2/0x23b
kernel_init+0x16/0x120
ret_from_fork+0x22/0x30

*Credits: N/A

CVSS Scores

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

* Common Vulnerability Scoring System

SSVC

Decision:Track

Exploitation

None

Automatable

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-04-10 CVE Reserved
2024-04-10 CVE Published
2024-04-11 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (6)

URL	Tag	Source
https://git.kernel.org/stable/c/93286261de1b46339aa27cd4c639b21778f6cade	Vuln. Introduced

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/b20ec58f8a6f4fef32cc71480ddf824584e24743	2021-11-26
https://git.kernel.org/stable/c/b0e44dfb4e4c699cca33ede431b8d127e6e8d661	2021-11-26
https://git.kernel.org/stable/c/9c177eee116cf888276d3748cb176e72562cfd5c	2021-11-26
https://git.kernel.org/stable/c/8823ea27fff6084bbb4bc71d15378fae0220b1d8	2021-11-25
https://git.kernel.org/stable/c/daf972118c517b91f74ff1731417feb4270625a4	2021-11-15

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 4.19.218 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 4.19.218"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 5.4.162 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.4.162"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 5.10.82 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.10.82"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 5.15.5 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.15.5"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.16 < 5.16 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.16 < 5.16"		en		Affected