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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2021-47430 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: x86/entry: Clear X86_FEATURE_SMAP when CONFIG_X86_SMAP=n Commit 3c73b81a9164 ("x86/entry, selftests: Further improve user entry sanity checks") added a warning if AC is set when in the kernel. Commit 662a0221893a3d ("x86/entry: Fix AC assertion") changed the warning to only fire if the CPU supports SMAP. However, the warning can still trigger on a machine that supports SMAP but where it's disabled in the kernel config and when running the syscall_nt selftest, for example: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 49 at irqentry_enter_from_user_mode CPU: 0 PID: 49 Comm: init Tainted: G T 5.15.0-rc4+ #98 e6202628ee053b4f310759978284bd8bb0ce6905 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 RIP: 0010:irqentry_enter_from_user_mode ... Call Trace: ? irqentry_enter ? exc_general_protection ? asm_exc_general_protection ? asm_exc_general_protectio IS_ENABLED(CONFIG_X86_SMAP) could be added to the warning condition, but even this would not be enough in case SMAP is disabled at boot time with the "nosmap" parameter. To be consistent with "nosmap" behaviour, clear X86_FEATURE_SMAP when !CONFIG_X86_SMAP. Found using entry-fuzz + satrandconfig. [ bp: Massage commit message. ]


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://git.kernel.org/stable/c/3958b9c34c2729597e182cc606cc43942fd19f7c CVE, kernel.org Patch 
https://git.kernel.org/stable/c/4e9ec1c65da98c293f75d83755dfa5e03075a6d0 CVE, kernel.org Patch 
https://git.kernel.org/stable/c/f2447f6587b8ffe42ba04d14ce67d429a1163e5e CVE, kernel.org Patch 

Weakness Enumeration

CWE-ID CWE Name Source
NVD-CWE-noinfo Insufficient Information cwe source acceptance level NIST  

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Change History

6 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-47430
NVD Published Date:
05/21/2024
NVD Last Modified:
06/17/2026
Source:
kernel.org