CVE-2026-63820 Details
Description
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix missing read bio submission on large folio error f2fs_read_data_large_folio() can keep a read bio across multiple readahead folios. If a later folio hits an error before any of its blocks are added to the bio, folio_in_bio is false and the current error path returns immediately after ending that folio. This can leave the bio accumulated for earlier folios unsubmitted. Those folios then never receive read completion, and readers can wait indefinitely on the locked folios. Route errors through the common out path so any pending bio is submitted before returning. Stop consuming more readahead folios once an error is seen, and only wait on and clear the current folio when it was actually added to the bio.
A vulnerability in the Linux kernel's F2FS (Flash-Friendly File System) can lead to a deadlock situation where read operations on large folios are not completed. This issue arises because the function responsible for reading data can retain a read bio (block I/O) across multiple readahead folios. If an error occurs with a later folio before its blocks are added to the bio, the folio is not considered part of the bio, and the error handling routine exits without submitting the bio. As a result, the bio for earlier folios remains unsubmitted, causing those folios to miss read completion. Readers can then be left waiting indefinitely on the locked folios.
Users can upgrade to the patched version of the Linux kernel available in the Linux kernel stable tree. The specific commit addressing this vulnerability is 48c92559e7b66fdc3cbc74f6e152e66ec0150a0a.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No CVSS 3.x data is available for this CVE.
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/48c92559e7b66fdc3cbc74f6e152e66ec0150a0a | kernel.org | |
| https://git.kernel.org/stable/c/74c8d2ec95c59a5651ecd975c466998af1961fd4 | kernel.org |
Weakness Enumeration
No weakness enumeration is available for this CVE.
Affected Products
No affected product data is available for this CVE.
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 17, 2026 | CVE Modified | kernel.org |
| Jul 19, 2026 | New CVE Received | kernel.org |