Linux Kernel up to 5.10.82/5.15.5 emergency_ctx stack-based overflow

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CTI Interest Score
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A vulnerability was found in Linux Kernel up to 5.10.82/5.15.5. It has been rated as critical. This issue affects the function emergency_ctx. The manipulation with an unknown input leads to a stack-based overflow vulnerability. Using CWE to declare the problem leads to CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: powerpc/32: Fix hardlockup on vmap stack overflow Since the commit c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") a vmap stack overflow results in a hard lockup. This is because emergency_ctx is still addressed with its virtual address allthough data MMU is not active anymore at that time. Fix it by using a physical address instead.

It is possible to read the advisory at The identification of this vulnerability is CVE-2021-47567. The exploitation is known to be easy. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/24/2024).

Upgrading to version 5.10.83 or 5.15.6 eliminates this vulnerability. Applying the patch dfe906da9a1a/c4e3ff8b8b1d/5bb60ea611db is able to eliminate this problem. The bugfix is ready for download at The best possible mitigation is suggested to be upgrading to the latest version.

The entries VDB-267464, VDB-267465, VDB-267466 and VDB-267467 are related to this item.







CPE 2.3info

CPE 2.2info


VulDB CVSS-B Score: 🔒
VulDB CVSS-BT Score: 🔒
VulDB Vector: 🔒
VulDB Reliability: 🔍


VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍



VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍


Class: Stack-based overflow
CWE: CWE-121 / CWE-119

Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒


Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍


Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.83/5.15.6
Patch: dfe906da9a1a/c4e3ff8b8b1d/5bb60ea611db


05/24/2024 Advisory disclosed
05/24/2024 +0 days VulDB entry created
05/24/2024 +0 days VulDB entry last update



Status: Confirmed

CVE: CVE-2021-47567 (🔒)
See also: 🔒


Created: 05/24/2024 06:43 PM
Changes: 05/24/2024 06:43 PM (56)
Complete: 🔍
Cache ID: 3:DB3:40


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