CVE-2022-49081

MEDIUM EPSS 13.2%
Published Feb 26, 20251y ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Feb 26, 2025 1y ago
Last Modified Jun 17, 2026 1w ago

Description

In the Linux kernel, the following vulnerability has been resolved: highmem: fix checks in __kmap_local_sched_{in,out} When CONFIG_DEBUG_KMAP_LOCAL is enabled __kmap_local_sched_{in,out} check that even slots in the tsk->kmap_ctrl.pteval are unmapped. The slots are initialized with 0 value, but the check is done with pte_none. 0 pte however does not necessarily mean that pte_none will return true. e.g. on xtensa it returns false, resulting in the following runtime warnings: WARNING: CPU: 0 PID: 101 at mm/highmem.c:627 __kmap_local_sched_out+0x51/0x108 CPU: 0 PID: 101 Comm: touch Not tainted 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13 Call Trace: dump_stack+0xc/0x40 __warn+0x8f/0x174 warn_slowpath_fmt+0x48/0xac __kmap_local_sched_out+0x51/0x108 __schedule+0x71a/0x9c4 preempt_schedule_irq+0xa0/0xe0 common_exception_return+0x5c/0x93 do_wp_page+0x30e/0x330 handle_mm_fault+0xa70/0xc3c do_page_fault+0x1d8/0x3c4 common_exception+0x7f/0x7f WARNING: CPU: 0 PID: 101 at mm/highmem.c:664 __kmap_local_sched_in+0x50/0xe0 CPU: 0 PID: 101 Comm: touch Tainted: G W 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13 Call Trace: dump_stack+0xc/0x40 __warn+0x8f/0x174 warn_slowpath_fmt+0x48/0xac __kmap_local_sched_in+0x50/0xe0 finish_task_switch$isra$0+0x1ce/0x2f8 __schedule+0x86e/0x9c4 preempt_schedule_irq+0xa0/0xe0 common_exception_return+0x5c/0x93 do_wp_page+0x30e/0x330 handle_mm_fault+0xa70/0xc3c do_page_fault+0x1d8/0x3c4 common_exception+0x7f/0x7f Fix it by replacing !pte_none(pteval) with pte_val(pteval) != 0.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
13.2% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 4

VendorProductVersionRange
linuxlinux_kernel*≥5.11  –  <5.15.34
linuxlinux_kernel*≥5.16  –  <5.16.20
linuxlinux_kernel*≥5.17  –  <5.17.3
linuxlinux_kernel5.18any

References 4

  • git.kernel.org https://git.kernel.org/stable/c/66f133ceab7456c789f70a242991ed1b27ba1c3d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7dd5b3b97716a611fcf67d92fd2370fcb8d50372
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/85550b0f5fa5dd3c30469ea702c44444ef242c83
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c21d040de6225414547d9bd31cd200f290991c85
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/66f133ceab7456c789f70a242991ed1b27ba1c3d
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7dd5b3b97716a611fcf67d92fd2370fcb8d50372
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/85550b0f5fa5dd3c30469ea702c44444ef242c83
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c21d040de6225414547d9bd31cd200f290991c85
    Patch