5.5

CVE-2021-46990: linux

CVSS: 5.5v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2021-46990DEBIAN-CVE-2021-46990
Published 28-02-2024Last modified 23-05-2026
Open JSON

Vulnerability summary

CVE-2021-46990 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 13% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.23%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 7 · Related 7
SUSE-SU-2024:1454-1SUSE-SU-2024:1465-1SUSE-SU-2024:1489-1SUSE-SU-2024:1643-1SUSE-SU-2024:1646-1SUSE-SU-2024:1870-1

Timeline

  1. 28-02-2024
    PublishedVulnerability first disclosed.
  2. 23-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: powerpc/64s: Fix crashes when toggling entry flush barrier The entry flush mitigation can be enabled/disabled at runtime via a debugfs file (entry_flush), which causes the kernel to patch itself to enable/disable the relevant mitigations. However depending on which mitigation we're using, it may not be safe to do that patching while other CPUs are active. For example the following crash: sleeper[15639]: segfault (11) at c000000000004c20 nip c000000000004c20 lr c000000000004c20 Shows that we returned to userspace with a corrupted LR that points into the kernel, due to executing the partially patched call to the fallback entry flush (ie. we missed the LR restore). Fix it by doing the patching under stop machine. The CPUs that aren't doing the patching will be spinning in the core of the stop machine logic. That is currently sufficient for our purposes, because none of the patching we do is to that code or anywhere in the vicinity.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.23%

Chance of exploitation in the next 30 days

Percentile

13%

Versus all other CVEs

30-day change

0.00 pp

From 0.23% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.23%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu86 products
  • linux< 4.4.0-253.287 | < 4.15.0-151.157 | < 5.4.0-80.90
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.4.0-1130.136 | < 4.4.0-1168.183 | < 4.15.0-1109.116 | < 5.4.0-1054.57
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 4a1e90af718d1489ffcecc8f52486c4f5dc0f7a6, < 8382b15864e5014261b4f36c2aa89723612ee058 | ≥ fa4bf9f38184ed7ca4916eb64f8c767d1e279c1f, < 0c25a7bb697f2e6ee65b6d63782f675bf129511a | ≥ db01cad9efe3c3838a6b3a3f68affd295c4b92d6, < ee4b7aab93c2631c3bb0753023c5dda592bb666b | ≥ f69bb4e51f41973fb7594be1479fa689831efe1a, < 2db22ba4e0e103f00e0512e0ecce36ac78c644f8 | ≥ b65458b6be8032c5179d4f562038575d7b3a6be3, < 0b4eb172cc12dc102cd0ad013e53ee4463db9508 | ≥ f79643787e0a0762d2409b7b8334e83f22d85695, < d2e3590ca39ccfd8a5a46d8c7f095cb6c7b9ae92 | ≥ f79643787e0a0762d2409b7b8334e83f22d85695, < dd0d6117052faace5440db20fc37175efe921c7d | ≥ f79643787e0a0762d2409b7b8334e83f22d85695, < 5bc00fdda1e934c557351a9c751a205293e68cbf | ≥ f79643787e0a0762d2409b7b8334e83f22d85695, < aec86b052df6541cc97c5fca44e5934cbea4963b | e590b36718d6e740b7b19514f710402a6499164c | ≥ 4.4.245, < 4.4.269 | ≥ 4.9.245, < 4.9.269 | ≥ 4.14.208, < 4.14.233 | ≥ 4.19.159, < 4.19.191 | ≥ 5.4.79, < 5.4.120 | ≥ 5.9.10, < 5.10 | 5.10
  • linux_kernel≥ 4.4.245, < 4.4.269 | ≥ 4.9.245, < 4.9.269 | ≥ 4.14.208, < 4.14.233 | ≥ 4.19.159, < 4.19.191 | ≥ 5.4.79, < 5.4.120 | ≥ 5.10, < 5.10.38 | ≥ 5.11, < 5.11.22 | ≥ 5.12, < 5.12.5 | 5.13:rc1
Debian1 product
  • linux< 5.10.38-1

3 vendors · 89 products

References

14 links
Show all 14 references