CVE-2021-46950: md/raid1: properly indicate failure when ending a failed write request

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-02-27 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: md/raid1: properly indicate failure when ending a failed write request This patch addresses a data corruption bug in raid1 arrays using bitmaps. Without this fix, the bitmap bits for the failed I/O end up being cleared. Since we are in the failure leg of raid1_end_write_request, the request either needs to be retried (R1BIO_WriteError) or failed (R1BIO_Degraded).

Affected products

Linux kernel: from 4.14.147 before 4.14.233; from 4.19.77 before 4.19.191; from 5.2.19 before 5.3; from 5.3.4 before 5.4.118; from 5.5 before 5.10.36; from 5.11 before 5.11.20 — fixed in 4.14.233, 4.19.191, 5.10.36, 5.11.20, 5.12.3, 5.3

How to fix

Upgrade to a fixed version: Linux kernel 4.14.233, 4.19.191, 5.10.36, 5.11.20. Check the vendor advisory for mitigations.

References

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