CVE-2026-31463
iomap: fix invalid folio access when i_blkbits differs from I/O granularity
Description
In the Linux kernel, the following vulnerability has been resolved: iomap: fix invalid folio access when i_blkbits differs from I/O granularity Commit aa35dd5cbc06 ("iomap: fix invalid folio access after folio_end_read()") partially addressed invalid folio access for folios without an ifs attached, but it did not handle the case where 1 << inode->i_blkbits matches the folio size but is different from the granularity used for the IO, which means IO can be submitted for less than the full folio for the !ifs case. In this case, the condition: if (*bytes_submitted == folio_len) ctx->cur_folio = NULL; in iomap_read_folio_iter() will not invalidate ctx->cur_folio, and iomap_read_end() will still be called on the folio even though the IO helper owns it and will finish the read on it. Fix this by unconditionally invalidating ctx->cur_folio for the !ifs case.
INFO
Published Date :
April 22, 2026, 2:16 p.m.
Last Modified :
April 22, 2026, 2:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to include commit aa35dd5cbc06.
- Apply the follow-up fix for iomap invalid folio access.
- Ensure i_blkbits matches IO granularity for folios.
- Validate folio access after read operations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-31463.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/4a927f670cdb0def226f9f85f42a9f19d9e09c88 | |
| https://git.kernel.org/stable/c/bd71fb3fea9945987053968f028a948997cba8cc |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-31463 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-31463
weaknesses.
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Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 22, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: iomap: fix invalid folio access when i_blkbits differs from I/O granularity Commit aa35dd5cbc06 ("iomap: fix invalid folio access after folio_end_read()") partially addressed invalid folio access for folios without an ifs attached, but it did not handle the case where 1 << inode->i_blkbits matches the folio size but is different from the granularity used for the IO, which means IO can be submitted for less than the full folio for the !ifs case. In this case, the condition: if (*bytes_submitted == folio_len) ctx->cur_folio = NULL; in iomap_read_folio_iter() will not invalidate ctx->cur_folio, and iomap_read_end() will still be called on the folio even though the IO helper owns it and will finish the read on it. Fix this by unconditionally invalidating ctx->cur_folio for the !ifs case. Added Reference https://git.kernel.org/stable/c/4a927f670cdb0def226f9f85f42a9f19d9e09c88 Added Reference https://git.kernel.org/stable/c/bd71fb3fea9945987053968f028a948997cba8cc