CVE-2026-64062: netfs: Fix potential deadlock in write-through mode
Vulnerability summary
CVE-2026-64062 is a medium (CVSS 5.5) Improper Locking vulnerability in linux. EPSS estimates a 0.09% chance of exploitation in the next 30 days, higher than 0.5% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 13 · Related 13Timeline
- 19-07-2026PublishedVulnerability first disclosed.
Description
In the Linux kernel, the following vulnerability has been resolved: netfs: Fix potential deadlock in write-through mode Fix netfs_advance_writethrough() to always unlock the supplied folio and to mark it dirty if it isn't yet written to the end. Unfortunately, it can't be marked for writeback until the folio is done with as that may cause a deadlock against mmapped reads and writes. Even though it has been marked dirty, premature writeback can't occur as the caller is holding both inode->i_rwsem (which will prevent concurrent truncation, fallocation, DIO and other writes) and ictx->wb_lock (which will cause flushing to wait and writeback to skip or wait). Note that this may be easier to deal with once the queuing of folios is split from the generation of subrequests.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.09%
Chance of exploitation in the next 30 days
Percentile
1%
Versus all other CVEs
30-day change
Decrease -0.03 pp
From 0.13% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu118 products
- linux< 7.0.0-28.28
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 7.0.0-1009.9
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 288ace2f57c9d06dd2e42bd80d03747d879a4068, < 1468f39243ccb155b6d97f9a9932f610d1205d75 | ≥ 288ace2f57c9d06dd2e42bd80d03747d879a4068, < 003aa0dd26c964025acd6d1213bcdbd674db2ca9 | ≥ 288ace2f57c9d06dd2e42bd80d03747d879a4068, < e40e9cbf3ee4d30ee9a97bd128c85500b6ad0da1 | ≥ 288ace2f57c9d06dd2e42bd80d03747d879a4068, < b6a4ae1634b3ad2aaa05222e53d36da532852faf | 6.10
- linux_kernel≥ 6.10, < 6.12.92 | ≥ 6.13, < 6.18.34 | ≥ 6.19, < 7.0.11 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3 | 7.1:rc4
Debian1 product
- linux< 6.12.94-1 | < 7.0.12-1
3 vendors · 121 products
