5.5

CVE-2021-47229: PCI: aardvark: Fix kernel panic during PIO transfer

Analyzed
AliasesUBUNTU-CVE-2021-47229DEBIAN-CVE-2021-47229
Published 21-05-2024Last modified 11-05-2026

Vulnerability summary

CVE-2021-47229 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 13.3% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.23%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 7 · Related 7

Timeline

  1. 21-05-2024
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: PCI: aardvark: Fix kernel panic during PIO transfer Trying to start a new PIO transfer by writing value 0 in PIO_START register when previous transfer has not yet completed (which is indicated by value 1 in PIO_START) causes an External Abort on CPU, which results in kernel panic: SError Interrupt on CPU0, code 0xbf000002 -- SError Kernel panic - not syncing: Asynchronous SError Interrupt To prevent kernel panic, it is required to reject a new PIO transfer when previous one has not finished yet. If previous PIO transfer is not finished yet, the kernel may issue a new PIO request only if the previous PIO transfer timed out. In the past the root cause of this issue was incorrectly identified (as it often happens during link retraining or after link down event) and special hack was implemented in Trusted Firmware to catch all SError events in EL3, to ignore errors with code 0xbf000002 and not forwarding any other errors to kernel and instead throw panic from EL3 Trusted Firmware handler. Links to discussion and patches about this issue: https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=3c7dcdac5c50 https://lore.kernel.org/linux-pci/20190316161243.29517-1-repk@triplefau.lt/ https://lore.kernel.org/linux-pci/971be151d24312cc533989a64bd454b4@www.loen.fr/ https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/1541 But the real cause was the fact that during link retraining or after link down event the PIO transfer may take longer time, up to the 1.44s until it times out. This increased probability that a new PIO transfer would be issued by kernel while previous one has not finished yet. After applying this change into the kernel, it is possible to revert the mentioned TF-A hack and SError events do not have to be caught in TF-A EL3.

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

No change 0.00 pp

From 0.23% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu87 products
  • linuxAll versions (No fix recorded) | < 4.15.0-156.163 | < 5.4.0-81.91
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 4.15.0-1111.118 | < 5.4.0-1055.58
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 8c39d710363c14ecb09219332869707395d1d495, < 400e6b1860c8be61388d0b77814c53260f96e17a | ≥ 8c39d710363c14ecb09219332869707395d1d495, < b00a9aaa4be20ad6e3311fb78a485eae0899e89a | ≥ 8c39d710363c14ecb09219332869707395d1d495, < 4c90f90a91d75c3c73dd633827c90e8746d9f54d | ≥ 8c39d710363c14ecb09219332869707395d1d495, < 1a1dbc4473974867fe8c5f195c17b341c8e82867 | ≥ 8c39d710363c14ecb09219332869707395d1d495, < 3d213a4ddf49a860be6e795482c17f87e0c82b2a | ≥ 8c39d710363c14ecb09219332869707395d1d495, < f18139966d072dab8e4398c95ce955a9742e04f7 | 4.8
  • linux_kernel< 4.14.240 | ≥ 4.15, < 4.19.198 | ≥ 4.20, < 5.4.128 | ≥ 5.5, < 5.10.46 | ≥ 5.11, < 5.12.13 | 5.13:rc1 | 5.13:rc2 | 5.13:rc3 | 5.13:rc4 | 5.13:rc5 | 5.13:rc6
Debian1 product
  • linux< 5.10.46-1

3 vendors · 90 products

References

10 links